condition mean min max ZT0-3 2.7480225000000003 2.7113 2.784745 ZT4-7 2.40003 2.40003 2.40003 ZT8-11 3.93754 3.93754 3.93754 ZT12-15 0 0 0 ZT16-19 6.038045 6.038045 6.038045 ZT20-23 5.306365 5.306365 5.306365