Year Number of 1990 1061.56 1991 1132.82 1992 1214.44 1993 1308.03 1994 1415.18 1995 1538.04 1996 1627.3 1997 1724.14 1998 1829.43 1999 1943.64 2000 2067.72 2001 2159.52 2002 2256.58 2003 2361.29 2004 2471.82 2005 2588.89 2006 2722.8 2007 2864.27 2008 3014.55 2009 3175.69 2010 3349.19 2011 3501.19 2012 3665.34 2013 3837.33 2014 4014.9 2015 4196.91 2016 4381.8