condition mean min max ZT0-3 5.5635725 5.155200000000001 5.971945 ZT4-7 7.731389999999999 7.731389999999999 7.731389999999999 ZT8-11 6.47814 6.47814 6.47814 ZT12-15 0 0 0 ZT16-19 6.65935 6.65935 6.65935 ZT20-23 5.87806 5.87806 5.87806