condition mean min max ZT0-3 6.155139999999999 5.760535 6.549745 ZT4-7 3.7907849999999996 3.7907849999999996 3.7907849999999996 ZT8-11 4.247095 4.247095 4.247095 ZT12-15 0 0 0 ZT16-19 5.064954999999999 5.064954999999999 5.064954999999999 ZT20-23 5.1699 5.1699 5.1699