condition mean min max ZT0-3 12.35 12.35 12.35 ZT4-7 6.7 6.7 6.7 ZT8-11 24.7 24.7 24.7 ZT12-15 8.4 8.4 8.4 ZT16-19 7.75 7.75 7.75 ZT20-23 6.6499999999999995 6.6499999999999995 6.6499999999999995