Year Number 1970 345800 1971 380500 1972 393000 1973 405000 1974 388300 1975 391300 1976 396000 1977 410000 1978 425000 1979 460000 1980 481000 1981 500000 1982 515000 1983 517000 1984 487000 1985 509000 1986 511000 1987 512000 1988 516000 1989 308000 1990 318500 1991 318500 1992 318500 1993 318500 1994 318500 1995 334500 1996 334500 1997 334500 1998 333200 1999 536800 2000 437600 2001 398216 2002 1186162 2003 1117208 2004 1392244 2005 1503624 2006 1620895 2007 1662866 2008 1637923 2009 1527346 2010 924207 2011 1539676 2012 1663425.4345762 2013 1572120 2014 1926969 2015 2095503 2016 2741388 2017 3149037 2018 3407788.43290303 2019 3701663.849 2020 1506581.713 2021 1132655.764