Year,Value,Contiguous U.S. (Lower 48),Precip,Jun,(in.)
1940,2.869
1941,3.415
1942,3.102
1943,2.851
1944,2.884
1945,3.478
1946,2.76
1947,3.891
1948,2.99
1949,3.036
1950,2.691
1951,3.424
1952,1.96
1953,2.337
1954,2.352
1955,2.391
1956,1.922
1957,3.407
1958,3.087
1959,2.595
1960,2.608
1961,2.727
1962,2.866
1963,2.781
1964,2.688
1965,2.821
1966,1.95
1967,3.297
1968,2.856
1969,2.99
1970,2.479
1971,2.091
1972,2.913
1973,2.874
1974,2.477
1975,3.065
1976,2.763
1977,2.483
1978,2.433
1979,2.509
1980,2.55
1981,3.394
1982,3.595
1983,3.167
1984,3.036
1985,2.804
1986,3.155
1987,2.871
1988,1.793
1989,4.05
1990,2.545
1991,2.847
1992,3.451
1993,3.726
1994,3.059
1995,3.402
1996,2.938
1997,3.461
1998,3.495
1999,3.202
2000,3.438
2001,2.991
2002,2.594
2003,3.457
2004,3.359
2005,2.958
2006,2.381
2007,2.714
2008,2.784
2009,3.095
2010,3.257
2011,2.536
2012,2.046
2013,3.108
2014,3.33
2015,3.182
2016,2.338
2017,3.063
2018,3.105
2019,3.343
2020,2.675
2021,2.949
2022,2.303
2023,2.855
2024,2.661
2025,3.293