condition mean min max ZT0-3 11.4532575 10.006565 12.89995 ZT4-7 16.33885 16.33885 16.33885 ZT8-11 21.24915 21.24915 21.24915 ZT12-15 0 0 0 ZT16-19 25.30755 25.30755 25.30755 ZT20-23 18.6057 18.6057 18.6057