condition mean min max ZT0-3 2.0546699999999998 1.93641 2.17293 ZT4-7 2.93514 2.93514 2.93514 ZT8-11 4.132225 4.132225 4.132225 ZT12-15 0 0 0 ZT16-19 3.097735 3.097735 3.097735 ZT20-23 3.2178 3.2178 3.2178