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 48000 1994 153000 1995 273000 1996 532000 1997 937700 1998 2047000 1999 3904000 2000 5932403 2001 7963742 2002 9314260 2003 8936202 2004 9324335 2005 10260396 2006 10979826 2007 12294912 2008 13799340 2009 13295093 2010 12292716 2011 12127985 2012 13360280 2013 12518645 2014 12144598 2015 12566649 2016 12538927 2017 12937106 2018 12170757 2019 11882081 2020 11412995 2021 11494008 2022 11326179