Year Number of 1990 720.42 1991 772.79 1992 841.01 1993 916.41 1994 994.97 1995 1066.94 1996 1147.59 1997 1251.79 1998 1360.24 1999 1481.86 2000 1594.76 2001 1706.21 2002 1815.16 2003 1918.69 2004 1989.56 2005 2120.68 2006 2293.45 2007 2441.26 2008 2590.58 2009 2782.36 2010 2961.47 2011 3067.86 2012 3141.94 2013 3131.39 2014 3155.91 2015 3181.64 2016 3221.77