Year	% of revenue
1984	31.25199957342434
1985	28.397972675187305
1986	29.401015228426395
1987	29.650396278167573
1988	30.28420957050758
1994	27.683660724423753
1995	27.873744534596284
1996	25.680230211603885
1997	29.655161754022597
1998	29.983959198782546
1999	31.90395365340482
2000	31.424177681778698
2001	30.94769403824522
2002	32.628003066962
2003	33.03932854863889
2004	35.404416354044166
2005	36.41938877160496
2006	36.836418940818945
2007	37.28663579022092
2008	38.285686494298126
2009	36.27259420950038
2010	38.4011005344275
2011	38.02307299241382
2012	35.37398833051007
2013	35.42782485264135
2014	35.5760246111751
2015	35.25169179324127
2016	36.44186734242072
2017	36.78744867001373
2018	36.77183338706417
2019	36.1730227186969
2020	35.71724942521441
2021	37.370474357761026
2022	35.60391260599187