condition mean min max ZT0-3 8.15 8.15 8.15 ZT4-7 1.2 1.2 1.2 ZT8-11 6.050000000000001 6.050000000000001 6.050000000000001 ZT12-15 5.6 5.6 5.6 ZT16-19 20.0 20.0 20.0 ZT20-23 10.9 10.9 10.9