condition mean min max ZT0-3 13.21222222 13.21222222 13.21222222 ZT4-7 10.56888889 10.56888889 10.56888889 ZT8-11 10.227222221 10.227222221 10.227222221 ZT12-15 15.29888889 15.29888889 15.29888889 ZT16-19 18.115555556666667 18.115555556666667 18.115555556666667 ZT20-23 16.07888889 16.07888889 16.07888889