condition mean min max ZT0-3 3.8042086527500003 2.5648774435000004 5.043539862 ZT4-7 8.511134154 7.170918831 9.851349477 ZT8-11 11.057233999166666 9.649342785 12.465125213333334 ZT12-15 15.605263945 14.14706542 17.06346247 ZT16-19 14.199480318333332 13.50515804 14.893802596666667 ZT20-23 11.38308508 9.859580161 12.906589999