condition mean min max ZT0-3 23.39705 23.39705 23.39705 ZT4-7 19.8273 19.8273 19.8273 ZT8-11 23.544150000000002 23.544150000000002 23.544150000000002 ZT12-15 21.840899999999998 21.840899999999998 21.840899999999998 ZT16-19 26.79025 26.79025 26.79025 ZT20-23 23.35775 23.35775 23.35775