Year Number of 1990 2265.22 1991 2432.99 1992 2547.86 1993 2701.8 1994 2850.69 1995 3000.78 1996 3067.02 1997 3174.27 1998 3216.95 1999 3360.21 2000 3287.76 2001 3288.18 2002 3255.81 2003 3381.63 2004 3307.87 2005 3308.22 2006 3285.78 2007 3154.05 2008 3058.08 2009 3409.55 2010 3514.8 2011 3645.96 2012 3709.93 2013 3919.3 2014 4032.24 2015 4169.8 2016 4325.08