Which language was the most popular to perform in and had the most winning entries in the years 1956-1998 in ESC?

Explanation

The winning entry was sung in French 15 times in the years 1956-1998 (e.g. André Claveau with "Dors, mon Amour" or Sandra Kim with "J'aime la Vie"), whilst the English language "won" 14 times in the same period(e.g. Brotherhood of Man with "Save Your Kisses for Me" and Johnny Logan with"Hold Me Now").