condition mean min max ZT0-3 11.643052 11.643052 11.643052 ZT4-7 11.5233595 11.5233595 11.5233595 ZT8-11 11.1284575 11.1284575 11.1284575 ZT12-15 9.898376500000001 9.898376500000001 9.898376500000001 ZT16-19 10.576918 10.576918 10.576918 ZT20-23 10.729081 10.729081 10.729081