condition mean min max ZT0-3 29.137825 25.1468 33.12885 ZT4-7 11.513 11.513 11.513 ZT8-11 10.8239 10.8239 10.8239 ZT12-15 0 0 0 ZT16-19 11.675725 11.675725 11.675725 ZT20-23 16.66965 16.66965 16.66965