Year Number of 1990 4026.14 1991 4079.51 1992 4187.87 1993 4292.7 1994 4367.87 1995 4425.75 1996 4275.54 1997 4046.37 1998 3825.6 1999 3630.65 2000 3473.75 2001 3407.11 2002 3368.75 2003 3365.11 2004 3396.8 2005 3415.27 2006 3353.39 2007 3249.19 2008 3040.45 2009 2892.95 2010 2786.13 2011 2731.43 2012 2679.68 2013 2591.55 2014 2476.75 2015 2435.66 2016 2537.4