condition mean min max ZT0-3 3.658028333333333 2.72598 4.18705 ZT4-7 4.01723 4.01723 4.01723 ZT8-11 3.42599 3.42599 3.42599 ZT12-15 8.9072325 8.599225 9.21524 ZT16-19 7.01989 7.01989 7.01989 ZT20-23 6.518224999999999 6.518224999999999 6.518224999999999