condition mean min max ZT0-3 7.92167 7.92167 7.92167 ZT4-7 9.1885875 9.1885875 9.1885875 ZT8-11 7.6066375 7.6066375 7.6066375 ZT12-15 8.172220500000002 8.172220500000002 8.172220500000002 ZT16-19 9.119764 9.119764 9.119764 ZT20-23 9.171211 9.171211 9.171211