condition mean min max ZT0-3 10.547495 8.61939 12.4756 ZT4-7 5.3452 5.3452 5.3452 ZT8-11 7.599615 7.599615 7.599615 ZT12-15 0 0 0 ZT16-19 8.318000000000001 8.318000000000001 8.318000000000001 ZT20-23 7.847315 7.847315 7.847315