I did not have figure about % of GDP, but in employment service and industry equally accounted for 44% of total labour force, which means that Service had a big part in British economy (although industry would be larger).
Germany: 34,5% Agri-37,9% Ind-27,6% Ser
http://www2.warwick.ac.uk/fac/soc/economics/staff/sbroadberry/wp/eurosector5a.pdf
Agriculture in Germany was very labour intensive.
And British industrial output was mostly from old, low-tech industries (textile, coal, clothing, footwear, outdated First Industrial Revolution machinery...).
You do know that British new industries, especially chemical, electrical and electronic equipment, and machinery significantly lagged behind Germany all the time.