condition mean min max ZT0-3 2.4090133333333337 2.22799 2.6456850000000003 ZT4-7 1.914395 1.914395 1.914395 ZT8-11 2.4204100000000004 2.4204100000000004 2.4204100000000004 ZT12-15 3.1400025 2.869065 3.41094 ZT16-19 2.167955 2.167955 2.167955 ZT20-23 2.5585649999999998 2.5585649999999998 2.5585649999999998