condition mean min max ZT0-3 6.98193 3.66625 13.2329 ZT4-7 24.08035 24.08035 24.08035 ZT8-11 27.73455 27.73455 27.73455 ZT12-15 13.992255 7.75436 20.23015 ZT16-19 7.314679999999999 7.314679999999999 7.314679999999999 ZT20-23 4.84342 4.84342 4.84342