Year Number of 1990 27476.79 1991 28531.44 1992 29584.6 1993 30418.35 1994 31390.64 1995 32461.62 1996 32244.99 1997 32079.76 1998 31873.44 1999 31592.28 2000 31307.74 2001 32005.75 2002 32704.73 2003 33443.15 2004 34100.99 2005 34855.57 2006 35121.2 2007 35425.85 2008 35675.97 2009 35947.3 2010 36301.63 2011 36618.83 2012 36998.75 2013 37333.05 2014 37691.69 2015 38490.52 2016 39446.97