distribution.dbo.MSdistribution_history comments explanation
http://social.msdn.microsoft.com/Forums/en-US/sqlreplication/thread/0b8bac44-da87-4115-90f6-b8bf1e1d0bd8

Both cmd values relate to the number of commands written. Since last stats - cmds are all cmds written since the last entry and stats- cmd are an accumulation of all cmds written since the last comment with a state of 1.