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 2195 1993 15699 1994 38942 1995 75000 1996 216900 1997 812200 1998 1928042 1999 3956500 2000 6747000 2001 10004661 2002 13898471 2003 17401222 2004 23096065 2005 29166391 2006 36745454 2007 41388774 2008 43926365 2009 44806632 2010 46952111 2011 50160222 2012 54086209 2013 56972803 2014 56905306 2015 54537230 2016 53001776 2017 50458854 2018 48285544 2019 48392944 2020 49350724 2021 50588734 2022 52589287