Democrat Presidents
I was watching this 1976 Gerald Ford campaign ad (love the music!) and that got me thiking that from 1969 to 2009 there would have been only 12 out of 40 years with Democratic Presidents.
In the 40 years before that though it was Republicans who only managed 12 out of 40 years.
Go back another 40 years for 1889 to 1929 and its is reveresed again with Republicans in for 28 years and Democrats for 12.
1849 to 1889 had it evenly split. 20 years of Democrats, 16 years of Republicans and four years of a Whig President.