Year Number of 1990 120.45 1991 124.23 1992 128.1 1993 132.22 1994 136.56 1995 141.26 1996 148.28 1997 155.85 1998 164.18 1999 173.27 2000 183.28 2001 192.72 2002 202.99 2003 214.13 2004 226.09 2005 238.98 2006 248.79 2007 258.91 2008 269.72 2009 281.38 2010 294.13 2011 304.84 2012 316.32 2013 328.19 2014 340.88 2015 354.46 2016 370.52