Year Number 1960 0 1965 0 1970 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 3260 1987 6720 1988 9573 1989 13492 1990 22285 1991 33749 1992 48586 1993 70222 1994 106902 1995 194185 1996 307485 1997 471395 1998 709596 1999 1101561 2000 1686452 2001 2329047 2002 2957717 2003 3577603 2004 4884774 2005 5736840 2006 6749024 2007 8005453 2008 9391122 2009 10081098 2010 10887695 2011 11831217 2012 12828717 2013 13248944 2014 14554739 2015 15129026 2016 16157539 2017 15928906 2018 15819685 2019 15792849 2020 15767955 2021 16654736 2022 17444565