condition mean min max ZT0-3 20.439063 20.439063 20.439063 ZT4-7 20.576376500000002 20.576376500000002 20.576376500000002 ZT8-11 22.6828905 22.6828905 22.6828905 ZT12-15 19.241174 19.241174 19.241174 ZT16-19 17.418514 17.418514 17.418514 ZT20-23 21.750922 21.750922 21.750922