Year % 1987 56.2 1990 57.2 1992 54.8 1994 56.4 1996 54.9 1998 55.5 2000 52.8 2003 51.5 2006 47.7 2009 47.4 2011 46.9 2013 46.8 2015 45.3 2017 45.3 2020 47 2022 43