What does the trade-to-GDP ratio measure? Does a low value indicate that a country is closed to trade with the outside world? Describe the pattern exhibited in the changes in the trade-to-GDP ratio...

What does the trade-to-GDP ratio measure? Does a low value indicate that a country is closed to trade with the outside world? Describe the pattern exhibited in the changes in the trade-to-GDP ratio and the composition of trade for leading industrial economies between 1910 and 1950.