condition mean min max ZT0-3 23.46295 23.46295 23.46295 ZT4-7 18.70115 18.70115 18.70115 ZT8-11 14.880700000000001 14.880700000000001 14.880700000000001 ZT12-15 17.4219 17.4219 17.4219 ZT16-19 19.747149999999998 19.747149999999998 19.747149999999998 ZT20-23 21.902900000000002 21.902900000000002 21.902900000000002