condition mean min max ZT0-3 2.683143333333333 2.3104050000000003 3.06914 ZT4-7 2.60503 2.60503 2.60503 ZT8-11 2.23422 2.23422 2.23422 ZT12-15 2.96558 2.600805 3.330355 ZT16-19 2.210025 2.210025 2.210025 ZT20-23 3.69199 3.69199 3.69199