btw, I found one....
http://www.usgovernmentdebt.us/spending_chart_1900_2015USp_13s1li011lcn_90s90l90f
So service costs got to 4% of GDP around 1990. We aren't even at 2.5% right now.(http://www.autoadmit.com/thread.php?thread_id=1863790&forum_id=2#19883871)