Year Number of 1990 296.41 1991 305.72 1992 331.51 1993 358.89 1994 388.18 1995 421.89 1996 430.67 1997 444.42 1998 457.27 1999 475.87 2000 495.55 2001 506.58 2002 526.26 2003 551.53 2004 579.59 2005 615.68 2006 633.61 2007 657.86 2008 684.91 2009 714.46 2010 744.51 2011 772.11 2012 801.7 2013 831.5 2014 859.57 2015 895.08 2016 931.09