Here is a better histogram:
http://www.us.archive.org/metamgr.php?f=histogram&group=operator&w_mediatype=texts&w_collection=microfilm*&w_scandate=201007*&w_scanner=microfilm*p.sanfrancisco.archive.org&w_operator=unknown*&w_repub_state=!null
Here is a better histogram:
http:// www.us. archive. org/metamgr. php?f=histogram &group= operator& w_mediatype= texts&w_ collection= microfilm* &w_scandate= 201007* &w_scanner= microfilm* p.sanfrancisco. archive. org&w_operator= unknown* &w_repub_ state=! null