Year Number 1960 138277 1961 140171 1962 142221 1963 144641 1964 147725 1965 151485 1966 155836 1967 160805 1968 166305 1969 172147 1970 178187 1971 184416 1972 190989 1973 197990 1974 205431 1975 213314 1976 221559 1977 230094 1978 238909 1979 248020 1980 257272 1981 266380 1982 275197 1983 283452 1984 290865 1985 297427 1986 303198 1987 308346 1988 313127 1989 317790 1990 322540 1991 327326 1992 331817 1993 335869 1994 339316 1995 342003 1996 344041 1997 346072 1998 348699 1999 351767 2000 355195 2001 359058 2002 363465 2003 368574 2004 374614 2005 382469 2006 392258 2007 402927 2008 413652 2009 423793 2010 432826 2011 441343 2012 449685 2013 458801 2014 468536 2015 478575 2016 489397 2017 500348 2018 511369 2019 522200 2020 529726 2021 533918 2022 538006 2023 544149