Year Number of 1990 3810.92 1991 3995.73 1992 4189.96 1993 4354.29 1994 4528.97 1995 4723.75 1996 4957.37 1997 5268.1 1998 5428.44 1999 5535.05 2000 5595.21 2001 5515.18 2002 5466.08 2003 5477.33 2004 5490.1 2005 5482.28 2006 5671.84 2007 5800.86 2008 5933.45 2009 6068.14 2010 6217.25 2011 6319.88 2012 6448.79 2013 6603.64 2014 6760.44 2015 6950.45 2016 7138.98