Year	% (modeled ILO estimate)
1991	33.703
1992	34.273
1993	34.763
1994	34.769
1995	34.787
1996	34.847
1997	35.042
1998	35.185
1999	35.363
2000	35.456
2001	35.589
2002	35.439
2003	35.546
2004	35.646
2005	35.738
2006	35.623
2007	35.587
2008	35.876
2009	36.121
2010	36.258
2011	35.967
2012	35.995
2013	36.303
2014	36.837
2015	37.184
2016	37.539
2017	38.004
2018	38.4
2019	38.232
2020	36.999
2021	37.124
2022	37.105
2023	37.351
