Year,Value,Contiguous U.S. (Lower 48),Temp,Mar-Apr,(°F)
1940,42.402
1941,41.913
1942,43.893
1943,43.83
1944,42.262
1945,45.737
1946,48.882
1947,42.438
1948,45.477
1949,46.348
1950,43.771
1951,44.118
1952,44.739
1953,46.213
1954,46.556
1955,46.433
1956,45.096
1957,46.002
1958,44.031
1959,46.725
1960,44.451
1961,46.131
1962,44.848
1963,47.915
1964,45.055
1965,43.7
1966,46.592
1967,47.489
1968,47.279
1969,44.498
1970,44.293
1971,45.335
1972,47.71
1973,46.788
1974,48.284
1975,43.096
1976,47.317
1977,49.033
1978,46.66
1979,46.345
1980,45.766
1981,49.38
1982,45.715
1983,44.989
1984,45.233
1985,49.181
1986,49.766
1987,48.267
1988,47.473
1989,48.174
1990,48.875
1991,48.288
1992,48.93
1993,46.154
1994,48.996
1995,46.692
1996,44.971
1997,46.148
1998,45.852
1999,47.031
2000,49.232
2001,47.116
2002,46.589
2003,47.643
2004,50.185
2005,47.725
2006,49.381
2007,49.548
2008,46.774
2009,47.438
2010,48.925
2011,48.139
2012,53.099
2013,46.093
2014,46.79
2015,50.076
2016,51.056
2017,50.581
2018,46.646
2019,47.349
2020,49.221
2021,49.423
2022,48.276
2023,46.633
2024,49.711
2025,51.037