Level 1 costs 50 billion, gives 1,000 troops with 5993 attack and defense each. So if you want the bonus from that it would be 5,993,000*0.02= 119,860 attack and defense. I don't know about level two or three stats but level two costs 150 billion for a fairly small stat gain.
U can search for BUILD CALCULATOR in forum. The excel file contains all the stats info u r looking for.