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 0 1992 0 1993 0 1994 0 1995 3500 1996 6644 1997 12500 1998 19500 1999 30000 2000 82000 2001 106600 2002 150000 2003 223671 2004 286095 2005 448857 2006 608846 2007 800270 2008 1052000 2009 1631576 2010 1950072 2011 2194495 2012 2146833 2013 2727913 2014 2670983 2015 2549817 2016 2659951 2017 2680196 2018 2759293 2019 2823655 2020 2898125 2021 2915307 2022 2905781