condition mean min max ZT0-3 5.0 5.0 5.0 ZT4-7 5.3 5.3 5.3 ZT8-11 6.550000000000001 6.550000000000001 6.550000000000001 ZT12-15 9.75 9.75 9.75 ZT16-19 4.35 4.35 4.35 ZT20-23 22.95 22.95 22.95