Year Number of 1990 945.88 1991 981.77 1992 1008.49 1993 1043.29 1994 1083.44 1995 1110.7 1996 1146.47 1997 1165.94 1998 1213.56 1999 1259.21 2000 1300.62 2001 1333.09 2002 1359.54 2003 1381.7 2004 1418.07 2005 1446.9 2006 1482.31 2007 1519.19 2008 1555.68 2009 1603.07 2010 1645.93 2011 1656.87 2012 1668.57 2013 1663.83 2014 1650.27 2015 1635.14 2016 1621.64