condition mean min max ZT0-3 6.7454 6.264 7.226800000000001 ZT4-7 6.451755 6.451755 6.451755 ZT8-11 9.002235 9.002235 9.002235 ZT12-15 0 0 0 ZT16-19 8.264965 8.264965 8.264965 ZT20-23 8.139565000000001 8.139565000000001 8.139565000000001