Year Number of 1990 2205.37 1991 2293.59 1992 2397.74 1993 2488.53 1994 2575.56 1995 2666.38 1996 2751.55 1997 2859.75 1998 2978.9 1999 3128.15 2000 3246.49 2001 3342.34 2002 3459.34 2003 3573.74 2004 3682.16 2005 3820.02 2006 3955.16 2007 4107.14 2008 4275.23 2009 4437.03 2010 4604.36 2011 4799.62 2012 4954.91 2013 5116.88 2014 5286.96 2015 5467.94 2016 5649.47