Year % 1987 61.4 1990 62.5 1992 60.1 1994 61.5 1996 60.1 1998 60.7 2000 58 2003 56.8 2006 53.8 2009 53.8 2011 53.4 2013 53.6 2015 52.1 2017 52 2020 53.3 2022 49.9