Year Number of 1990 126.27 1991 130.36 1992 133.7 1993 140.32 1994 145.7 1995 151.81 1996 157.69 1997 165.81 1998 174.32 1999 181.43 2000 191.38 2001 202.76 2002 215.69 2003 229.87 2004 244.42 2005 258.97 2006 268.28 2007 277.88 2008 288.61 2009 301.51 2010 316.8 2011 330.13 2012 344.19 2013 358.22 2014 372.25 2015 386.89 2016 405.38