Year Number of 1990 2774.7 1991 2848.19 1992 2924.48 1993 3006.86 1994 3093.59 1995 3176.49 1996 3262.86 1997 3349.57 1998 3443.64 1999 3518.96 2000 3594.44 2001 3646.64 2002 3701.08 2003 3757.07 2004 3801.57 2005 3844.6 2006 3866.46 2007 3889.51 2008 3925.46 2009 3971.72 2010 4024.23 2011 4065.17 2012 4101.54 2013 4130.93 2014 4170.9 2015 4216.86 2016 4271.35