Year,Value,Contiguous U.S. (Lower 48),Wind,Mar,(mph)
1940,7.637
1941,7.479
1942,8.197
1943,8.288
1944,8.214
1945,7.967
1946,8.258
1947,7.801
1948,8.48
1949,7.855
1950,8.959
1951,8.895
1952,8.254
1953,8.341
1954,8.459
1955,8.718
1956,8.506
1957,7.83
1958,7.071
1959,8.604
1960,7.93
1961,8.387
1962,8.107
1963,8.538
1964,8.6
1965,7.939
1966,8.228
1967,8.255
1968,8.128
1969,7.893
1970,7.659
1971,8.667
1972,8.149
1973,8.02
1974,8.446
1975,8.659
1976,8.674
1977,8.911
1978,7.4
1979,8.081
1980,8.486
1981,7.675
1982,8.235
1983,8.161
1984,7.828
1985,8.403
1986,7.857
1987,7.892
1988,8.46
1989,7.897
1990,7.555
1991,8.73
1992,7.187
1993,7.459
1994,7.767
1995,7.878
1996,8.19
1997,8.196
1998,7.91
1999,8.039
2000,7.628
2001,7.171
2002,8.129
2003,7.598
2004,7.978
2005,7.823
2006,8.25
2007,7.883
2008,8.18
2009,8.422
2010,7.713
2011,8.238
2012,8.446
2013,7.859
2014,8.255
2015,7.176
2016,8.187
2017,8.389
2018,8.075
2019,7.725
2020,7.907
2021,8.334
2022,8.365
2023,8.273
2024,7.995
2025,8.76