condition mean min max ZT0-3 5.4373475 4.984835 5.88986 ZT4-7 2.9928850000000002 2.9928850000000002 2.9928850000000002 ZT8-11 3.38966 3.38966 3.38966 ZT12-15 0 0 0 ZT16-19 4.462149999999999 4.462149999999999 4.462149999999999 ZT20-23 5.77924 5.77924 5.77924