why has berkshire hathaway exceeded the returns of the S&P 500 by such a substantial amount ?

following is an attanchment of the performance between bershire and the S&P 500

Berkshire's Performance vs. the S&P 500 22 Year 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 Annual Percentage Change in Per-Share in S&P 500 Market Value of with Dividends Berkshire Included 49 $ 10.0 (3.4) (117) 133 30.9 77.8 11.0 19.4 (84) (4.6) 3.9 80.5 14.6 8.1 18.9 (2.5) (14.8) (48.7) 2.5 372 23.6 129.3 21.8 2017 2018 2019 2020 Compounded Annual Gain 1965-2020 Overall Gain 1964-2020 21.9 2.8 11.0 2.4 20.0% 2.810,526% 31.5 18.4 10.2% 23.454% Berkshire's Performance vs. the S&P 500 22 Year 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 Annual Percentage Change in Per-Share in S&P 500 Market Value of with Dividends Berkshire Included 49 $ 10.0 (3.4) (117) 133 30.9 77.8 11.0 19.4 (84) (4.6) 3.9 80.5 14.6 8.1 18.9 (2.5) (14.8) (48.7) 2.5 372 23.6 129.3 21.8 2017 2018 2019 2020 Compounded Annual Gain 1965-2020 Overall Gain 1964-2020 21.9 2.8 11.0 2.4 20.0% 2.810,526% 31.5 18.4 10.2% 23.454%