Year Number of 1990 185577.99 1991 189809.1 1992 194539.13 1993 199502.97 1994 204380.83 1995 209600.9 1996 210834.16 1997 212409.26 1998 214200.12 1999 215865.03 2000 217599.36 2001 217706.69 2002 218074.08 2003 218556.92 2004 219141.21 2005 219927.14 2006 222012.16 2007 224381.39 2008 226858.31 2009 229503.16 2010 232261.69 2011 236774.11 2012 241430.93 2013 245998.39 2014 250188.41 2015 254840.01 2016 259633.55