YEAR,PARTY,RD_Difference
1940,D,9.1
1944,D,7.5
1948,D,4.4
1952,R,10.5
1956,R,15.4
1960,D,0.2
1964,D,21.8
1968,R,0.7
1972,R,23.2
1976,D,2.1
1980,R,9.7
1984,R,18.2
1988,R,7.8
1992,D,3.6
1996,D,8.5
2000,R,0.5
2004,R,2.4
2008,D,7.2
2012,D,3.3