Correlates of War Database
I have taken the Correlates of War database from Correlates of War Project, interpolated missing data and added % of world for 6 different military/economic factors: Military Expenditures, Military Personnel, Iron/Steel Production, Personal Energy Consumption, Urban Population, Total Population covering the period 1816-2012.
This should be useful in creating scenarios. The data has flaws, but it is the only comprehensive database of military power. The values reflect the territory controlled by the government at that time. Note that the names used reflect continuity but are often anachronistic. The Soviet Union is always called Russia, Prussia is always called Germany.
For comparison, economic data is available under the The Maddison Database.
The file is too large to post here. See Wiki Page