condition mean min max ZT0-3 7.87688 7.87688 7.87688 ZT4-7 5.92935 5.92935 5.92935 ZT8-11 5.73875 5.73875 5.73875 ZT12-15 7.356325 7.356325 7.356325 ZT16-19 11.94705 11.94705 11.94705 ZT20-23 7.6103499999999995 7.6103499999999995 7.6103499999999995