condition mean min max ZT0-3 9.008837499999998 8.876505 9.141169999999999 ZT4-7 8.753135 8.753135 8.753135 ZT8-11 10.60739 10.60739 10.60739 ZT12-15 0 0 0 ZT16-19 16.433149999999998 16.433149999999998 16.433149999999998 ZT20-23 14.5311 14.5311 14.5311