Year Number of 1990 1556.88 1991 1549.64 1992 1654.74 1993 1760.2 1994 1812.61 1995 1925.54 1996 1978.88 1997 1989.82 1998 2069.7 1999 2117.55 2000 2147.26 2001 2165.22 2002 2195.82 2003 2248.17 2004 2275.7 2005 2326.3 2006 2392.74 2007 2430.53 2008 2483 2009 2523.09 2010 2559.72 2011 2586.69 2012 2609.32 2013 2623.33 2014 2633.06 2015 2661.52 2016 2695.12