condition mean min max ZT0-3 8.0389025 7.418515 8.65929 ZT4-7 8.10528 8.10528 8.10528 ZT8-11 9.959859999999999 9.959859999999999 9.959859999999999 ZT12-15 0 0 0 ZT16-19 12.792449999999999 12.792449999999999 12.792449999999999 ZT20-23 10.7085 10.7085 10.7085