12-Year Interval

The corresponding interval from an important high to a low is 12 years plus a few months. A low usually lies somewhere between 12 years, 2 months and 12 years, 8 months.

Examine the long-term interval from high to low that began on December 13, 1961. According to precedent, it should have ended not later than 12 years and 8 months afterward. That would place it in August 1974. There have been only two occasions in the past 100 years when it exceeded that duration materially. One was in 1970 and another in 1974. In both cases, the time elapsed was 12 years, 10 months. So, the low of 1974 came 2 months later than it should have. An overrun of 2 months is not excessive when we are referring to a span of 12 years or so.