Year Number of 1990 4811.89 1991 4731.11 1992 4643.99 1993 4563.57 1994 4446.77 1995 4376.31 1996 4272.91 1997 4202.13 1998 4112.3 1999 4001.69 2000 3874.52 2001 3833.15 2002 3779.63 2003 3702.42 2004 3592.69 2005 3507.5 2006 3408.56 2007 3347.8 2008 3281.33 2009 3193.88 2010 3168.78 2011 3147.56 2012 3165.69 2013 3166.18 2014 3151.56 2015 3140.52 2016 3162.59