Year Number 1970 578000 1971 550400 1972 566500 1973 579900 1974 613700 1975 634000 1976 654400 1977 632000 1978 649600 1979 687200 1980 769800 1981 737900 1982 814300 1983 905500 1984 941400 1985 929700 1986 943100 1987 975800 1988 940300 1989 950600 1990 996500 1991 1008200 1992 1017600 1993 1080800 1994 1137200 1995 1149300 1996 1217900 1997 1424700 1998 1492900 1999 1610600 2000 1456463 2001 1446879 2002 1368294 2003 1227248 2004 1266467 2005 1313815 2006 1345358 2007 1464994 2008 1421962 2009 1471241 2010 1932829.9372299917 2011 2031106.146271812 2012 2153840.9082252607 2013 2253790.415076939 2014 2357197.271872366 2015 2447053 2016 2383083 2017 2361676 2018 2422241.325865347 2019 2450088 2020 1130964.27 2021 1585996.8530000001