Year	% of revenue
1990	23.890189826117282
1991	21.83803457688808
1992	27.33107992761788
2000	24.09399201028427
2001	23.968919492858017
2002	20.64712562553913
2003	20.429600223070025
2004	18.814394484969828
2005	26.197276636181904
2006	19.164455447263933
2007	20.416718205977826
2008	19.310523025007118
2009	22.60243169783947
2010	23.598392065888333
2011	27.680556508501176
2012	18.057455813494215
2013	23.546079788685987
2014	21.610984055018555
2015	23.83196325571539
2016	26.07808495030598
2017	22.014912532978542
2018	23.377593033315026
2019	23.48177660286178
2020	17.924742690244575
2021	24.450192787430996
2022	25.033504723929