When early dreadnoughts would enter reserve

When would Britain relegate its 12-inch and 13.5-inch dreadnoughts without the First World War?

From roughly 1916-1918, beginning with 12-inch battleships as the R class entered service; larger-gunned ships would last longer.

Without the First World War, replacement would still accelerate as newer 15-inch battleships entered service. The 12-inch battleships would move first into reserve or colonial roles, while 13.5-inch ships remained longer. The 12-inch battlecruisers would follow as a new fast-capital-ship generation appeared.