condition mean min max ZT0-3 9.073849404 8.144698615 10.003000193 ZT4-7 7.686752379 7.233032632 8.140472126 ZT8-11 5.81293265325 5.730610394 5.8952549125 ZT12-15 4.03684066225 3.8721256219999995 4.2015557025 ZT16-19 4.31298038675 3.8640613555 4.761899418 ZT20-23 7.63172391825 6.696267353 8.5671804835