condition mean min max ZT0-3 4.412201666666667 2.6000050000000003 5.701855 ZT4-7 2.573925 2.573925 2.573925 ZT8-11 9.07165 9.07165 9.07165 ZT12-15 8.30376 6.36698 10.24054 ZT16-19 6.12177 6.12177 6.12177 ZT20-23 8.18561 8.18561 8.18561