condition mean min max ZT0-3 6.9 6.9 6.9 ZT4-7 15.4 15.4 15.4 ZT8-11 32.6 32.6 32.6 ZT12-15 29.099999999999998 29.099999999999998 29.099999999999998 ZT16-19 5.699999999999999 5.699999999999999 5.699999999999999 ZT20-23 6.050000000000001 6.050000000000001 6.050000000000001