Year Number of 1990 2019.89 1991 2052.41 1992 2084.13 1993 2112.7 1994 2141.51 1995 2174.61 1996 2259.19 1997 2354.73 1998 2460.99 1999 2576.43 2000 2702.15 2001 2851.75 2002 3015.59 2003 3197.85 2004 3401.17 2005 3630.5 2006 3780.43 2007 3942.6 2008 4116.93 2009 4299.73 2010 4498.28 2011 4620.55 2012 4746.26 2013 4869.58 2014 4995.95 2015 5128.04 2016 5260.64