Year Number 1970 380320 1971 399657.6 1972 411040.9 1973 466158.9 1974 495859.3 1975 556098.9 1976 594378.4 1977 643485.1 1978 713409.4 1979 801921.3 1980 899235.5 1981 1009940 1982 1089166 1983 1164389 1984 1220487 1985 1297884 1986 1262072 1987 1312214 1988 1366718 1989 1309824 1990 1324353 1991 1327931 1992 1359860 1993 1417182 1994 1494841 1995 1579159 1996 1620273 1997 1650880 1998 1679952 1999 1708263 2000 1826451 2001 1904294 2002 1972809 2003 2074598 2004 2133122 2005 2150871 2006 2218454 2007 2375236 2008 2585660 2009 2796206 2010 3013148 2011 3109136 2012 3208970 2013 3312909 2014 3450019 2015 3454520 2016 3483640 2017 3550089 2018 3654092