condition mean min max ZT0-3 8.759226 8.759226 8.759226 ZT4-7 8.2998855 8.2998855 8.2998855 ZT8-11 8.241377 8.241377 8.241377 ZT12-15 8.241377 8.241377 8.241377 ZT16-19 8.155202 8.155202 8.155202 ZT20-23 8.215525 8.215525 8.215525