When Britain would need to start a 37-cruiser program

When would Britain need to begin production to have 37 light cruisers ready by the start of the Second World War?

Around 1932, at an approximate sustained rate of eight cruisers per year.

Working backward from a fleet ready in 1939 produces a seven-year program beginning in about 1932 to deliver thirty-seven cruisers. The implied rate is roughly eight ships per year once yard capacity and overlapping construction are considered. The alternate fleet list therefore requires a demanding industrial tempo and years of advance commitment.