How to calculate annualized returns given table of DCF?

I was reading the Dhandho Investor by Mohinish Pabrai, and I came acorss this table:

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In context to this table the author goes in to say that for and investment of 5000$ the owner makes a 21 bagger. He further adds on to say that the annualized return in well over 50%. Could someone tell me how is the annualized return calculated here? Because each time I tried to calculate it I get approx 36%.