Year Number of 1990 2177.01 1991 2338.21 1992 2486.08 1993 2635.52 1994 2784.29 1995 2921.18 1996 3031.89 1997 3067.17 1998 3118.72 1999 3156.56 2000 3181.43 2001 3221.35 2002 3253.27 2003 3280.31 2004 3306.84 2005 3320.03 2006 3324.91 2007 3331.88 2008 3370.45 2009 3417.72 2010 3468.31 2011 3486.87 2012 3563.36 2013 3700.92 2014 3860.36 2015 4030.41 2016 4199.14