Year Number 1978 3597439 1979 3568371.5 1980 3520765.25 1981 3510087.75 1982 3475699.75 1983 3487692 1984 3511504.75 1985 3604676 1986 3734868 1987 3864535.5 1988 3982343 1989 4088683.25 1990 4210156.5 1991 4304390.5 1992 4383412.5 1993 4481607 1994 4571197.5 1995 4686354 1996 4903833 1997 5084953.5 1998 5353825 1999 5589854 2000 5743358 2001 5753456 2002 6135876 2003 6379384.5 2004 6531122 2005 6643068 2006 6310182 2007 6488705 2008 6636923.5 2009 6698834 2010 6754537.5 2011 6798224.5 2012 6891769 2013 6744351.5 2014 6819200.5 2015 6905524 2016 7000929 2017 7113103.5 2018 7248795 2019 7399338.5 2020 7216558.5 2021 7882349.5 2022 8127961