Percentage of years in which the “Great Powers” did not fight each other, data aggregated over 25 year periods
- 1795–1820: 35 % no wars between great powers
- 1835–1860: 75 % no wars between great powers
- 1875–1900: 90 % no wars between great powers
- 1915–1940: 60 % no wars between great powers
- 1955–1980: 90 % no wars between great powers
- 1990–2015: 100 % no wars between great powers