condition mean min max ZT0-3 17.999299999999998 16.7515 19.2471 ZT4-7 12.08165 12.08165 12.08165 ZT8-11 23.14295 23.14295 23.14295 ZT12-15 0 0 0 ZT16-19 26.5595 26.5595 26.5595 ZT20-23 19.4194 19.4194 19.4194