condition mean min max ZT0-3 10.471861 10.471861 10.471861 ZT4-7 11.5370265 11.5370265 11.5370265 ZT8-11 10.901628500000001 10.901628500000001 10.901628500000001 ZT12-15 12.0170195 12.0170195 12.0170195 ZT16-19 12.580451499999999 12.580451499999999 12.580451499999999 ZT20-23 11.860062500000002 11.860062500000002 11.860062500000002