It doesn't look like the information about posts being migrated (PostHistory.PostHistoryType=17) is stored in the data dump. The best data we have is is in the migrations section of the 10k tools
In the last 90 days
SU 323
SO 77
U&L 44
DBA 33
Apple 32
Webmasters 27
AskUbuntu 20
Security 17
mSF 1
Others 12 to 6 different sites
-- Edit Zypher --
All time data from a "magical source"
superuser.com 2943
stackoverflow.com 2799
webmasters.stackexchange.com 238
unix.stackexchange.com 140
dba.stackexchange.com 80
askubuntu.com 76
apple.stackexchange.com 69
security.stackexchange.com 51
meta.serverfault.com 34
webapps.stackexchange.com 25
