condition mean min max ZT0-3 3.4711125000000003 3.152715 3.78951 ZT4-7 5.19456 5.19456 5.19456 ZT8-11 15.75865 15.75865 15.75865 ZT12-15 0 0 0 ZT16-19 13.810649999999999 13.810649999999999 13.810649999999999 ZT20-23 5.0546500000000005 5.0546500000000005 5.0546500000000005