Year	% of revenue
1984	20.57415868295983
1986	19.586767363396113
1987	27.784875619144856
1988	28.900242992276315
1989	34.368487208156765
1991	37.75142845802622
1992	33.69820579960769
1993	35.78626190170222
1994	38.81796684368903
1995	41.89016623910258
1996	41.1694045057356
1997	37.99147056244941
1998	39.11699343193252
1999	32.88001319563707
2000	42.344074368057285
2001	35.76219976171124
2002	38.71484463328797
2003	35.14554093168041
2004	33.150477631703396
2005	34.30468699632519
2006	37.63746188779844
2007	36.0472253529856
2008	38.59118973007132
2009	37.49807675994918
2010	45.616922403283205
2011	41.22992506864444
2012	41.05047363532373
2013	38.21571326647989
2014	34.00236119365777
2015	33.63906402205652
2016	35.176824493004844
2017	33.46112327382807
2018	33.21287517745107
2019	31.706056436763813
2020	34.710033703635624
2021	38.06504161963661
2022	36.58178664578274