Manufacturing (the only thing you can export) is only 5% of the UK economy.
Manufacturing is around and about 10% of the UK economy. And services exports are quite large really:
Total UK exports of services (excluding travel, transport and banking) in current prices continued to rise, increasing from £103,828 million in 2012 to £117,193 million in 2013, an increase of 12.9%.
Total UK exports of services to Europe witnessed the largest increase in 2013 rising from £51,963 million in 2012 to £57,150 million, an increase of 10.0%. Exports to Germany contributed most towards the increase.
The professional, scientific and technical activities sector continued to be the largest sector contributing 27.4% of total UK exports in 2013.
Total UK imports of services (excluding travel, transport and banking) in current prices increased by 15.1% rising from £46,399 million in 2012 to £53,387 million in 2013.
Services exports are some 7 or 8% of the UK economy. The services trade surplus is some 3 or 4% of the economy, summat like that.