Year Number 1960 18016186 1961 18164949 1962 18436194 1963 18791002 1964 19180281 1965 19505716 1966 19817592 1967 20194041 1968 20576909 1969 20927782 1970 21208613 1971 21473819 1972 21786087 1973 22090640 1974 22366109 1975 22597278 1976 22789948 1977 22946418 1978 23069644 1979 23187013 1980 23345419 1981 23539855 1982 23735300 1983 23930817 1984 24093967 1985 24215120 1986 24332200 1987 24442324 1988 24528173 1989 24630450 1990 24764298 1991 24911597 1992 25071370 1993 25225455 1994 25376674 1995 25522188 1996 25667217 1997 25839020 1998 26047030 1999 26258283 2000 26207082 2001 26397266 2002 26536166 2003 26665100 2004 26785845 2005 26892993 2006 26987088 2007 27072534 2008 27148245 2009 27207210 2010 27149441 2011 27117387 2012 26990755 2013 26811365 2014 26609308 2015 26396251 2016 26160735 2017 25909730 2018 25647760 2019 25389267 2020 25118729 2021 24835510 2022 24410950 2023 24405465