condition mean min max ZT0-3 12.75 12.75 12.75 ZT4-7 25.6 25.6 25.6 ZT8-11 27.049999999999997 27.049999999999997 27.049999999999997 ZT12-15 23.25 23.25 23.25 ZT16-19 18.450000000000003 18.450000000000003 18.450000000000003 ZT20-23 11.15 11.15 11.15