condition mean min max ZT0-3 37.54695 37.54695 37.54695 ZT4-7 33.956450000000004 33.956450000000004 33.956450000000004 ZT8-11 22.2575 22.2575 22.2575 ZT12-15 22.499000000000002 22.499000000000002 22.499000000000002 ZT16-19 26.924599999999998 26.924599999999998 26.924599999999998 ZT20-23 30.7293 30.7293 30.7293