[knz]

Why stop at five years? How does this compare to job openings in 1776?

More seriously, bounds have to be set on a comparison like this for it to have relevance.

https://en.m.wikipedia.org/wiki/Stock_market_cycles#Short_te... suggests that "Cyclical cycles generally last 4 years, with bull and bear market phases lasting 1–3 years, while Secular cycles last about 30 years with bull and bear market phases lasting 10–20 years."

Assuming this is true or widely accepted by economists, four years seems like an appropriate length of time for a comparison such as this.