Year	% of revenue
1990	26.82869348575875
1991	35.29184373559981
1992	35.166032316370604
1993	30.77394678339156
2001	14.802725455684246
2002	20.909992477071633
2003	33.5060862894335
2004	34.915823309106955
2005	35.90354124205148
2006	36.55870437265173
2007	33.83689461412678
2008	33.077852898372306
2009	29.34761485421266
2010	27.506398943316647
2011	27.436738508065346
2012	26.784316770174975
2013	26.197779267088695
2014	27.530921807581016
2015	33.81687367825976
2016	37.946571396308045
2017	33.61884161799302
2018	31.552075068113695
2019	32.13149095437403
2020	32.26815975995771
2021	35.284936858640755
2022	32.47944622506767