condition mean min max ZT0-3 2.26674243325 2.2479474405 2.285537426 ZT4-7 3.4608347884999997 2.3367383299999998 4.584931247 ZT8-11 6.0165713835000005 5.7765106955 6.2566320715 ZT12-15 5.606592150999999 5.1221640399999995 6.091020262 ZT16-19 5.2406303055 4.3422956195 6.1389649915 ZT20-23 8.312040394 7.410200852999999 9.213879935000001