Year	% of revenue
1983	20.1346778786559
1984	22.54863281842736
1985	21.932205193699446
1986	21.16800036686309
1987	21.06747305344786
1988	22.430102376818535
1989	25.432249516114364
1990	25.728791716659998
1991	33.82587645185039
1992	31.76629318692627
1993	33.86043028131575
1994	34.91608806723137
1995	30.67757976029205
1996	33.53207486161248
1997	34.20750906409381
1998	33.97357012079547
1999	36.922896877831846
2000	34.26664185700331
2001	35.81021087680355
2002	35.27936909456142
2003	34.61318535587884
2004	36.890133059482935
2005	36.96277007399708
2006	37.19172140130347
2007	35.14747995418099
2008	33.37609349607551
2009	34.41383827762743
2010	19.15449256630884
2011	33.425312729948494
2012	34.86247799359289
2013	34.97039442592799
2014	34.26104342030917
2015	34.77021423635107
2016	36.48028150508462
2017	35.39458978702824
2018	29.90963405499953
2019	28.95337521838342
2020	27.737806089495987
2021	31.53553240029697
2022	33.863761012056045