Year Total 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 364960 1979 613740 1980 779170 1981 918080 1982 1005200 1983 1247700 1984 1568400 1985 1996500 1986 2335000 1987 2615300 1988 2631800 1989 2731500 1990 2951200 1991 2992900 1992 3270700 1993 3139400 1994 3287200 1995 4604300 1996 4978100 1997 5662600 1998 5879800 1999 6196700 2000 9855700 2001 14729000 2002 15894000 2003 17509000 2004 17816000 2005 19909000 2006 23196000 2007 23497000 2008 23392000 2009 24306000 2010 26402000 2011 27817000 2012 28962000 2013 31310000 2014 29957000 2015 31268000 2016 31879000