| Characteristic | End of year | Average |
|---|---|---|
| 2021 | 36,338.3 | 34,055.29 |
| 2020 | 30,606.48 | 26,890.67 |
| 2019 | 28,538.44 | 26,379.55 |
| 2018 | 23,327.46 | 25,046.86 |
| 2017 | 24,719.22 | 21,750.2 |
| 2016 | 19,762.6 | 17,927.11 |
| 2015 | 17,425.03 | 17,587.03 |
| 2014 | 17,823.07 | 16,777.69 |
| 2013 | 16,576.66 | 15,009.52 |
| 2012 | 13,104.14 | 12,966.44 |
| 2011 | 12,217.56 | 11,957.57 |
| 2010 | 11,577.51 | 10,668.58 |
| 2009 | 10,428.05 | 8,885.65 |
| 2008 | 8,776.39 | 11,244.06 |
| 2007 | 13,264.82 | 13,178.26 |
| 2006 | 12,463.15 | 11,409.78 |
| 2005 | 10,717.5 | 10,546.66 |
| 2004 | 10,783.01 | 10,315.51 |
| 2003 | 10,453.92 | 9,006.64 |
| 2002 | 8,341.63 | 9,214.85 |
| 2001 | 10,021.57 | 10,199.29 |
| 2000 | 10,787.99 | 10,729.38 |
| 1999 | 11,497.12 | 10,481.56 |
| 1998 | 9,181.43 | 8,630.76 |
| 1997 | 7,908.3 | 7,447.01 |
| 1996 | 6,448.27 | 5,739.63 |
| 1995 | 5,117.12 | 4,494.28 |
| 1994 | 3,834.44 | 3,794.22 |
| 1993 | 3,754.09 | 3,524.92 |
| 1992 | 3,301.11 | 3,284.08 |
| 1991 | 3,168.83 | 2,929.04 |
| 1990 | 2,633.66 | 2,679.45 |
| 1989 | 2,753.2 | 2,510.33 |
| 1988 | 2,168.57 | 2,061.48 |
| 1987 | 1,938.83 | 2,277.53 |
| 1986 | 1,895.95 | 1,793.1 |
| 1985 | 1,546.67 | 1,327.99 |
| 1984 | 1,211.57 | 1,178.59 |
| 1983 | 1,258.64 | 1,190.78 |
| 1982 | 1,046.54 | 884.53 |
| 1981 | 875 | 932.95 |
| 1980 | 963.99 | 891.14 |
| 1979 | 838.74 | 844.38 |
| 1978 | 805.01 | 821.13 |
| 1977 | 831.17 | 894.37 |
| 1976 | 1,004.65 | 975.2 |
| 1975 | 852.41 | 802.89 |
| 1974 | 616.24 | 759.13 |
| 1973 | 850.86 | 924.07 |
| 1972 | 1,020.02 | 950.08 |
| 1971 | 890.2 | 884.87 |
| 1970 | 838.92 | 753.12 |
| 1969 | 800.36 | 875.72 |
| 1968 | 943.75 | 903.96 |
| 1967 | 905.11 | 879.48 |
| 1966 | 785.69 | 872.78 |
| 1965 | 969.26 | 910.7 |
| 1964 | 874.13 | 834.09 |
| 1963 | 762.95 | 714.69 |
| 1962 | 652.1 | 639.14 |
| 1961 | 731.14 | 691.74 |
| 1960 | 615.89 | 618.02 |
| 1959 | 679.36 | 632.57 |
| 1958 | 583.65 | 491.26 |
| 1957 | 435.69 | 476.07 |
| 1956 | 499.47 | 493.21 |
| 1955 | 488.4 | 442.69 |
| 1954 | 404.39 | 334.34 |
| 1953 | 280.9 | 275.84 |
| 1952 | 291.9 | 270.35 |
| 1951 | 269.23 | 257.41 |
| 1950 | 235.41 | 216.28 |
| 1949 | 200.13 | 179.67 |
| 1948 | 177.3 | 179.78 |
| 1947 | 181.16 | 177.48 |
| 1946 | 177.2 | 191.52 |
| 1945 | 192.91 | 169.66 |
| 1944 | 152.32 | 143.32 |
| 1943 | 135.89 | 134.92 |
| 1942 | 119.4 | 107.15 |
| 1941 | 110.96 | 121.93 |
| 1940 | 131.13 | 134.64 |
| 1939 | 150.24 | 142.57 |
| 1938 | 154.76 | 132.36 |
| 1937 | 120.85 | 166.45 |
| 1936 | 179.9 | 162.07 |
| 1935 | 144.13 | 120.35 |
| 1934 | 104.04 | 98.16 |
| 1933 | 99.9 | 84.5 |
| 1932 | 59.93 | 64.53 |
| 1931 | 77.9 | 138.6 |
| 1930 | 164.58 | 236.04 |
| 1929 | 248.48 | 313.54 |
| 1928 | 300 | 226.17 |
| 1927 | 200.7 | 176.07 |
| 1926 | 157.2 | 153 |
| 1925 | 151.08 | 134.4 |
| 1924 | 120.51 | 99.65 |
| 1923 | 95.52 | 94.87 |
| 1922 | 98.17 | 93.24 |
| 1921 | 80.8 | 73.39 |
| 1920 | 71.95 | 90.01 |
| 1919 | 107.23 | 99.79 |
| 1918 | 82.2 | 80.97 |
| 1917 | 74.38 | 87.87 |
| 1916 | 95 | 95.27 |
| 1915 | 99.15 | 74.45 |
The chart is not accessible to screen readers. Please switch to the table view to access the data.
Loading statistic...
Download
Source
Release date
June 2022
Region
United States
Survey time period
1915 to 2021
Citation formats









