condition mean min max ZT0-3 3.1710450000000003 2.95471 3.3873800000000003 ZT4-7 2.4959949999999997 2.4959949999999997 2.4959949999999997 ZT8-11 4.2797149999999995 4.2797149999999995 4.2797149999999995 ZT12-15 0 0 0 ZT16-19 4.454975 4.454975 4.454975 ZT20-23 3.94773 3.94773 3.94773