Year Number 1960 351959 1961 356677 1962 363434 1963 371067 1964 379618 1965 388217 1966 396029 1967 402140 1968 407694 1969 413785 1970 419615 1971 425032 1972 430001 1973 435058 1974 440453 1975 445759 1976 450256 1977 454311 1978 457996 1979 460776 1980 463684 1981 467419 1982 471541 1983 475383 1984 479751 1985 485066 1986 490284 1987 495068 1988 498544 1989 500495 1990 501113 1991 498710 1992 487875 1993 473479 1994 462791 1995 454097 1996 447579 1997 443525 1998 441480 1999 448264 2000 455232 2001 453931 2002 452541 2003 451377 2004 450242 2005 448772 2006 446092 2007 443333 2008 441915 2009 440752 2010 438949 2011 436127 2012 432444 2013 428725 2014 425349 2015 423826 2016 422355 2017 421626 2018 422780 2019 424046 2020 424011 2021 423870 2022 429181 2023 433912