Year,Value,Contiguous U.S. (Lower 48),Precip,Sep-Nov,(cm)
1940,15.653
1941,18.768
1942,15.398
1943,12.191
1944,16.124
1945,19.75
1946,21.685
1947,17.678
1948,17.554
1949,16.005
1950,17.524
1951,18.799
1952,10.651
1953,12.548
1954,14.364
1955,15.809
1956,12.54
1957,23.011
1958,17.285
1959,21.139
1960,17.201
1961,19.068
1962,17.433
1963,15.507
1964,15.795
1965,17.437
1966,15.289
1967,16.553
1968,18.245
1969,16.02
1970,20.371
1971,18.502
1972,21.337
1973,23.143
1974,17.179
1975,18.298
1976,15.196
1977,21.995
1978,16.366
1979,17.689
1980,17.181
1981,19.598
1982,21.371
1983,23.772
1984,22.879
1985,26.464
1986,25.718
1987,16.477
1988,20.1
1989,17.244
1990,18.154
1991,19.158
1992,19.113
1993,18.378
1994,20.277
1995,19.131
1996,23.21
1997,18.813
1998,20.45
1999,13.944
2000,17.915
2001,17.649
2002,19.345
2003,18.207
2004,23.333
2005,16.27
2006,20.781
2007,15.392
2008,17.463
2009,21.731
2010,17.689
2011,18.06
2012,14.801
2013,18.066
2014,17.903
2015,20.949
2016,17.917
2017,17.652
2018,25.311
2019,20.168
2020,17.27
2021,17.849
2022,15.651
2023,14.891
2024,17.096