It's a well known portfolio so it has been analyzed quite a bit.

You can backtest it yourself:

https://www.portfoliovisualizer.com/backtest-asset-class-all...

- portfolio 1 is all stocks

- portfolio 2 is 75% stocks, 25% cash

- portfolio 3 is the "Harry Browne Permanent Porfolio" (selected from the "lazy portolios" option)

Take a look at the "drawdowns" tab.