Year | Value | 2022 | 17,749,120 | 2021 | 18,455,787 | 2020 | 18,743,926 | 2019 | 18,884,780 | 2018 | 18,904,579 | 2017 | 18,771,806 | 2016 | 18,465,207 | 2015 | 18,151,665 | 2014 | 17,865,719 | 2013 | 17,545,166 | 2012 | 17,263,173 | 2011 | 17,092,641 | 2010 | 16,917,241 | 2009 | 16,723,471 | 2008 | 16,533,804 | 2007 | 16,355,225 | 2006 | 16,177,687 | 2005 | 15,947,155 | 2004 | 15,707,970 | 2003 | 15,545,765 | 2002 | 15,406,016 | 2001 | 15,233,176 | 2000 | 15,133,573 | 1999 | 15,173,046 | 1998 | 15,322,623 | 1997 | 15,560,144 | 1996 | 15,937,507 | 1995 | 16,394,135 | 1994 | 16,809,869 | 1993 | 17,071,118 | 1992 | 17,213,190 | 1991 | 17,238,244 | 1990 | 17,131,954 | 1989 | 17,016,713 | 1988 | 16,853,526 | 1987 | 16,584,319 | 1986 | 16,273,718 | 1985 | 15,947,638 | 1984 | 15,626,541 | 1983 | 15,221,895 | 1982 | 14,730,743 | 1981 | 14,186,535 | 1980 | 13,269,552 | 1979 | 11,983,760 | 1978 | 10,749,406 | 1977 | 9,836,753 | 1976 | 9,521,066 | 1975 | 9,988,852 | 1974 | 11,063,505 | 1973 | 12,414,287 | 1972 | 13,694,604 | 1971 | 14,402,288 | 1970 | 14,487,845 | 1969 | 14,099,224 | 1968 | 13,366,269 | 1967 | 12,697,633 | 1966 | 12,283,359 | 1965 | 12,274,472 | 1964 | 12,621,731 | 1963 | 13,216,933 | 1962 | 13,699,620 | 1961 | 13,986,544 | 1960 | 14,073,900 |
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