condition mean min max ZT0-3 6.20815 6.20815 6.20815 ZT4-7 3.379175 3.379175 3.379175 ZT8-11 4.352155 4.352155 4.352155 ZT12-15 6.5198350000000005 6.5198350000000005 6.5198350000000005 ZT16-19 9.005365000000001 9.005365000000001 9.005365000000001 ZT20-23 8.519175 8.519175 8.519175