Year Number of 1990 2705.6 1991 2799.53 1992 2894.33 1993 2990.58 1994 3094.47 1995 3211.71 1996 3335.44 1997 3476.93 1998 3639.85 1999 3814.87 2000 4001.37 2001 4142.11 2002 4291.85 2003 4457.34 2004 4624.02 2005 4794.35 2006 4908.83 2007 5016.17 2008 5141.87 2009 5275.62 2010 5423.93 2011 5572 2012 5734.29 2013 5910.15 2014 6091.23 2015 6275.31 2016 6463.11