condition mean min max ZT0-3 9.538025 9.538025 9.538025 ZT4-7 8.2086615 8.2086615 8.2086615 ZT8-11 8.0389965 8.0389965 8.0389965 ZT12-15 8.7963265 8.7963265 8.7963265 ZT16-19 8.417071 8.417071 8.417071 ZT20-23 7.8219765 7.8219765 7.8219765