If the virtual-network is deleted, the derived stats of the corresponding virtual-network doesn't get deleted.

root@nodec41(analytics):/# curl -u admin:contrail123 localhost:8181/analytics/uves/virtual-network/default-domain:ctest-WebuiTestSanity-08644118:left_vn?flat | python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1218    0  1218    0     0  75333      0 --:--:-- --:--:-- --:--:-- 76125
{
    "AggProxySum-UveVirtualNetworkAgent-egress_flow_count": {
        "deleted": false,
        "proxy": "UveVirtualNetworkAgent-egress_flow_count",
        "value": {
            "value": 0
        }
    },
    "AggProxySum-UveVirtualNetworkAgent-ingress_flow_count": {
        "deleted": false,
        "proxy": "UveVirtualNetworkAgent-ingress_flow_count",
        "value": {
            "value": 0
        }
    },
    "RoutingInstanceStatsData": {
        "ermvpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:left_vn:left_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "evpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:left_vn:left_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv4_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:left_vn:left_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv6_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:left_vn:left_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        }
    }
}

root@nodec41(analytics):/# curl -u admin:contrail123 localhost:8181/analytics/uves/virtual-network/default-domain:ctest-WebuiTestSanity-84112158:vn-test?flat | python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   912    0   912    0     0   127k      0 --:--:-- --:--:-- --:--:--  148k
{
    "RoutingInstanceStatsData": {
        "ermvpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-84112158:vn-test:vn-test\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "evpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-84112158:vn-test:vn-test\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv4_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-84112158:vn-test:vn-test\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv6_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-84112158:vn-test:vn-test\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        }
    }
}

root@nodec41(analytics):/# curl -u admin:contrail123 localhost:8181/analytics/uves/virtual-network/default-domain:ctest-WebuiTestSanity-08644118:right_vn?flat | python -m json.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1226    0  1226    0     0  75279      0 --:--:-- --:--:-- --:--:-- 76625
{
    "AggProxySum-UveVirtualNetworkAgent-egress_flow_count": {
        "deleted": false,
        "proxy": "UveVirtualNetworkAgent-egress_flow_count",
        "value": {
            "value": 0
        }
    },
    "AggProxySum-UveVirtualNetworkAgent-ingress_flow_count": {
        "deleted": false,
        "proxy": "UveVirtualNetworkAgent-ingress_flow_count",
        "value": {
            "value": 0
        }
    },
    "RoutingInstanceStatsData": {
        "ermvpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:right_vn:right_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "evpn_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:right_vn:right_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv4_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:right_vn:right_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        },
        "ipv6_stats": {
            "nodec41:Control:contrail-control:0:\"default-domain:ctest-WebuiTestSanity-08644118:right_vn:right_vn\"": {
                "infeasible_paths": 0,
                "prefixes": 0,
                "primary_paths": 0,
                "secondary_paths": 0,
                "total_paths": 0
            }
        }
    }
}