condition mean min max ZT0-3 0.944547646 0.39302998899999997 1.496065303 ZT4-7 1.96307538825 1.8114482215 2.114702555 ZT8-11 1.41513123875 1.2614700205 1.568792457 ZT12-15 1.0037773644999999 0.9075281159999999 1.1000266129999998 ZT16-19 1.2068677922500002 0.925319679 1.4884159055000001 ZT20-23 1.4253044395 1.148046844 1.7025620350000001