condition mean min max ZT0-3 15.956755 11.379909999999999 20.5336 ZT4-7 7.93844 7.93844 7.93844 ZT8-11 5.98626 5.98626 5.98626 ZT12-15 0 0 0 ZT16-19 6.93178 6.93178 6.93178 ZT20-23 8.646525 8.646525 8.646525