Private Equity Fund Performance Measurement

ABC Capital is evaluating the performance of its private equity fund, which has been active for five years. The fund's net asset value (NAV) has increased from $50 million at the start to $85 million at the end of this period. In addition, the fund has distributed $20 million back to its investors during these five years.

To assess the fund’s performance, ABC Capital is considering various metrics including the Internal Rate of Return (IRR) and the Multiple on Invested Capital (MOIC).

What is the most appropriate measure for evaluating the fund's performance in terms of actual cash returned to investors compared to the amount they invested?