condition mean min max ZT0-3 7.5829075 7.34516 7.820655 ZT4-7 7.957425 7.957425 7.957425 ZT8-11 7.584205 7.584205 7.584205 ZT12-15 0 0 0 ZT16-19 9.612655 9.612655 9.612655 ZT20-23 10.22195 10.22195 10.22195