Year	% of total
1988	34.6
1991	36.5
1992	40.7
1993	40.7
1995	46.2
1996	46.3
1997	56.4
1998	55.2
2000	60.9
2003	69.4
2005	74.2
2008	78.9
2014	91.5
2021	97.1