2000, 2008 Stock Market Crashes

It  took 2 years after the internet bubble until the stock market hit the bottom and start the recovery movement. During the 2000 year market crash the S&P 500 dropped by 50%. It took more than 4 years for the S&P 500 to recover and reach the same high levels.

It took only a year for the S&P 500 to crash down for 42% now and we still do not see the end... How long will it take to recover from this hole???