Year Number 1970 748276.9375 1971 772284.5 1972 839696.0625 1973 888764.6875 1974 935145.5 1975 985559.3125 1976 1038918.125 1977 1101358.625 1978 1153951.375 1979 1216594.875 1980 1285343.875 1981 1359531.5 1982 1437005 1983 1558044.75 1984 1664078.25 1985 1790562.125 1986 1897650.25 1987 2015310.75 1988 2106766.25 1989 2166649.75 1990 2304898.25 1991 2410931.5 1992 2497826.25 1993 2580352.25 1994 2675476.75 1995 2772916.5 1996 2878517.5 1997 2973427 1998 3053871.25 1999 3138047 2000 3256702.25 2001 3292194.5 2002 3500086.25 2003 3695375.75 2004 3777604 2005 4079259 2006 4387977 2007 4736872.5 2008 5045253.5 2009 5296907 2010 5548120 2011 5724899 2012 5737611 2013 5862070 2014 6028249.5 2015 6211510.5 2016 6593815.5 2017 6830495 2018 7334368 2019 7827308 2020 8184243.5 2021 8289934.5 2022 8387281