condition mean min max ZT0-3 7.7075949999999995 7.7075949999999995 7.7075949999999995 ZT4-7 5.322229999999999 5.322229999999999 5.322229999999999 ZT8-11 5.394615 5.394615 5.394615 ZT12-15 6.4067799999999995 6.4067799999999995 6.4067799999999995 ZT16-19 9.359089999999998 9.359089999999998 9.359089999999998 ZT20-23 9.136105 9.136105 9.136105