Bear Markets since WWII

Depending on how one defines a bear market there have been many sustained declines in stock prices over the past 40 years. Most market experts consider the stock market in 'bear' phase once stocks have sunk 20% or more from their all time highs.

Often market experts break down market phases in larger cycles, called secular bull or bear markets. A secular bear markets is one where the previous highs are not achieved for extended periods of time. The Japanese stock market for example has been in a secular bear market since late 1989, when the Nikkei Dow Jones peaked at around 39,000 points.  A secular bull market can experience 20 percent declines as long as the decline is recovered quickly and followed by new highs. 
The table below represents bear markets in the United States since 1957.

Recent US Bear Markets

Year(s)	Pctg. decline	No. of mos. from peak to bottom	No. of mos. to recover 100% of loss	P/E at
1957	20%	3	12	11.5
1961-62	29	6	14	14.5
1966	22	9	6	13.0
1968-70	37	18	22	15.0
1973-74	48	21	64	7.0
1980	22	2	4	6.5
1981-82	22	13	3	8.0
1987	34	2	23	13.0
1990	20	3	5	14.0
Average	28	9	17	11.4