condition mean min max ZT0-3 8.098518 8.098518 8.098518 ZT4-7 10.5295875 10.5295875 10.5295875 ZT8-11 8.948263 8.948263 8.948263 ZT12-15 8.919040500000001 8.919040500000001 8.919040500000001 ZT16-19 8.948263 8.948263 8.948263 ZT20-23 8.6247395 8.6247395 8.6247395