Year	%
1988	36.67694
1990	31.57342
1991	29.62195
1993	46.96391
1996	23.56364
1997	39.10907
1999	35.16729
2000	29.28895
2001	32.40295
2002	26.13922
2003	26.67545
2004	24.00313
2005	22.15667
2006	19.82903
2007	18.87357
2008	25.17838
2009	17.92559
2010	17.38737
2011	23.04758
2012	18.71627
2013	22.40447
2014	22.22947
2015	21.93327
2016	22.46038
2017	23.10005
2018	17.63853
2019	17.82999
2020	19.19075
2021	19.78361