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 0 1987 0 1988 0 1989 0 1990 0 1991 426 1992 1277 1993 1679 1994 2599 1995 6353 1996 9534 1997 17140 1998 26307 1999 38659 2000 161860 2001 256106 2002 262772 2003 336352 2004 651189 2005 924100 2006 1518800 2007 1509800 2008 1806120 2009 1846345 2010 1894240 2011 1826200 2012 1883683 2013 1943873 2014 1980566 2015 2123374 2016 2165847 2017 2030637 2018 1972595 2019 2163725 2020 1987996 2021 1996837 2022 1999029