The UK’s net EU budget contribution in 2014 was £9.8 billion https://commonslibrary.parliament.uk/research-briefings/cbp-...
Meanwhile the UK exported $276 billion worth of good to the EU more than half of its total https://www.worldstopexports.com/united-kingdoms-top-import-...
Not counting anything else just these two we could say the EU had a 3.6% tariff on UK imports (insanely low! check https://www.wto.org/english/res_e/statis_e/daily_update_e/ta... -- and note the post brexit deal only created a 0% tariff on goods and not services). And even that is a severe exaggeration because there were other benefits to this.
On the other hand, the way these things went it's very likely the UK already contributed to the EERP but got nothing out of it.