Year Number of 1990 1984.04 1991 2024.09 1992 2066.36 1993 2115.96 1994 2170.03 1995 2229.78 1996 2287.36 1997 2348.52 1998 2420.5 1999 2496.31 2000 2575.79 2001 2642.48 2002 2714.97 2003 2802.1 2004 2890.76 2005 2981.42 2006 3080.5 2007 3181.75 2008 3292.98 2009 3409.76 2010 3533.69 2011 3682.12 2012 3836.83 2013 3997.59 2014 4163.59 2015 4336.09 2016 4512.03