condition mean min max ZT0-3 218.577352 218.577352 218.577352 ZT4-7 260.7416295 260.7416295 260.7416295 ZT8-11 301.71756000000005 301.71756000000005 301.71756000000005 ZT12-15 229.19010649999998 229.19010649999998 229.19010649999998 ZT16-19 239.5416715 239.5416715 239.5416715 ZT20-23 234.858339 234.858339 234.858339