condition mean min max ZT0-3 7.050000000000001 7.050000000000001 7.050000000000001 ZT4-7 11.7 11.7 11.7 ZT8-11 15.850000000000001 15.850000000000001 15.850000000000001 ZT12-15 7.25 7.25 7.25 ZT16-19 5.6 5.6 5.6 ZT20-23 14.299999999999999 14.299999999999999 14.299999999999999