Year Number of 1990 1660.11 1991 1671.86 1992 1667.71 1993 1675.57 1994 1677.22 1995 1688.33 1996 1689.79 1997 1673.8 1998 1687.09 1999 1706.92 2000 1718 2001 1715.19 2002 1709.11 2003 1711.15 2004 1747.63 2005 1725.25 2006 1698.09 2007 1690.4 2008 1685.07 2009 1650.32 2010 1620.17 2011 1615.71 2012 1652.23 2013 1663.23 2014 1660.3 2015 1695.45 2016 1716.97