Year % of population 1990 100 1991 100 1992 100 1993 100 1994 100 1995 100 1996 100 1997 100 1998 100 1999 100 2000 99.9 2001 99.9 2002 99.8 2003 99.8 2004 99.7 2005 99.7 2006 99.7 2007 99.7 2008 99.7 2009 100 2010 100 2011 99.8 2012 99.9 2013 99.9 2014 99.9 2015 100 2016 100 2017 100 2018 100 2019 100 2020 100 2021 100 2022 100