Where in UI does show you total Resource To Market % and numbers? I can not find it anywhere.
@goodcigar
Kazakk is correct. You can click on the Trade tab or you can also use the hotkey "R" on your keyboard to get to the Trade screen.
To see your Trade Law, click on your country flag to open the Political screen and then either hover your mouse pointer over the Trade Law icon to reveal a tooltip or click on the Trade Law icon to open the Trade Law screen. In the screenshots below, you should see that Turkey is currently on the Export Focus Trade Law where one half (50%) of all extracted resources are available for trade. You should also see a tooltip that shows 25 steel (approximately 50% of the 51 steel extracted) is being exported to Portugal, Finland, Afghanistan, Estonia, and Lithuania.