Year Number of 1990 445.55 1991 471.79 1992 500.63 1993 531.37 1994 565.59 1995 603.85 1996 649.66 1997 699.92 1998 755.6 1999 815.62 2000 879.64 2001 900.77 2002 923.35 2003 947.37 2004 972.37 2005 998.93 2006 1027.93 2007 1059.01 2008 1093.61 2009 1133.47 2010 1179.25 2011 1214.9 2012 1255.27 2013 1296.34 2014 1339.91 2015 1385.43 2016 1431.75