Year Number 1960 17909356 1961 18271000 1962 18614000 1963 18964000 1964 19325000 1965 19678000 1966 20048000 1967 20412000 1968 20744000 1969 21028000 1970 21324000 1971 21962032 1972 22218463 1973 22491777 1974 22807969 1975 23143275 1976 23449808 1977 23725843 1978 23963203 1979 24201544 1980 24515667 1981 24819915 1982 25116942 1983 25366451 1984 25607053 1985 25842116 1986 26100278 1987 26446601 1988 26791747 1989 27276781 1990 27691138 1991 28037420 1992 28371264 1993 28684764 1994 29000663 1995 29302311 1996 29610218 1997 29905948 1998 30155173 1999 30401286 2000 30685730 2001 31020855 2002 31359199 2003 31642461 2004 31938807 2005 32242732 2006 32571193 2007 32888886 2008 33247298 2009 33630069 2010 34005902 2011 34339221 2012 34713395 2013 35080992 2014 35434066 2015 35704498 2016 36110803 2017 36545075 2018 37072620 2019 37618495 2020 38028638 2021 38239864 2022 38939056 2023 40097761