condition mean min max ZT0-3 20.760779 20.760779 20.760779 ZT4-7 17.527223499999998 17.527223499999998 17.527223499999998 ZT8-11 18.496601 18.496601 18.496601 ZT12-15 16.9556035 16.9556035 16.9556035 ZT16-19 16.569055499999997 16.569055499999997 16.569055499999997 ZT20-23 16.045703500000002 16.045703500000002 16.045703500000002