How combat exposure changed from sail to global war

What proportion of ships actually engaged in combat, and how did that differ between the age of sail and the Second World War?

Many sailing warships could pass through a war without firing in anger, while global air and submarine threats exposed a much larger share of Second World War ships to attack.

Combat exposure was uneven in the age of sail and far more widespread during the Second World War. A sailing warship might serve throughout a conflict without firing its guns, whereas ships in the 1940s were much more likely to face air attack, submarine attack, or another form of engagement. Modern weapons made support and patrol vessels part of the combat zone.