Year Per 100 People 1970 1.76889 1975 3.31552 1976 3.44574 1977 3.56378 1978 3.5992 1979 3.56461 1980 3.53216 1981 3.67039 1982 3.72588 1983 3.787 1984 3.79885 1985 5.18679 1986 5.70353 1987 6.61026 1988 7.5092 1989 8.42703 1990 12.20222 1991 13.57152 1992 14.4496 1993 15.24257 1994 15.88473 1995 16.86613 1996 17.90516 1997 18.97893 1998 19.50019 1999 21.90489 2000 23.08291 2001 24.14898 2002 25.26492 2003 19.55699 2004 17.52227 2005 20.69539 2006 20.78838 2007 21.02488 2008 20.86475 2009 21.06944 2010 19.85363 2011 20.78177 2012 17.72556 2013 17.44329 2014 21.85777 2015 22.7171 2016 18.74265 2017 18.29986