condition mean min max ZT0-3 158.140415 158.140415 158.140415 ZT4-7 432.1381745 432.1381745 432.1381745 ZT8-11 274.771309 274.771309 274.771309 ZT12-15 166.527733 166.527733 166.527733 ZT16-19 105.314445 105.314445 105.314445 ZT20-23 146.479894 146.479894 146.479894