Year Number of 1990 2097.24 1991 2118.15 1992 2131 1993 2151.11 1994 2143.41 1995 2136.29 1996 2139.27 1997 2123.81 1998 2130.94 1999 2142.17 2000 2128.31 2001 2132.78 2002 2144.8 2003 2130.27 2004 2110.47 2005 2070.22 2006 2037.29 2007 2013.97 2008 1993.01 2009 1988.9 2010 1969.8 2011 1938.36 2012 1919.34 2013 1892.58 2014 1873.97 2015 1858.04 2016 1884.44