condition mean min max ZT0-3 21.896575 20.95645 22.8367 ZT4-7 7.17301 7.17301 7.17301 ZT8-11 16.02005 16.02005 16.02005 ZT12-15 0 0 0 ZT16-19 36.75635 36.75635 36.75635 ZT20-23 36.503699999999995 36.503699999999995 36.503699999999995