condition mean min max ZT0-3 7.6 7.6 7.6 ZT4-7 5.5 5.5 5.5 ZT8-11 4.5 4.5 4.5 ZT12-15 6.050000000000001 6.050000000000001 6.050000000000001 ZT16-19 22.75 22.75 22.75 ZT20-23 7.699999999999999 7.699999999999999 7.699999999999999