condition mean min max ZT0-3 12.320973 12.320973 12.320973 ZT4-7 11.8547035 11.8547035 11.8547035 ZT8-11 11.831034500000001 11.831034500000001 11.831034500000001 ZT12-15 12.244619499999999 12.244619499999999 12.244619499999999 ZT16-19 10.3554825 10.3554825 10.3554825 ZT20-23 10.782293500000002 10.782293500000002 10.782293500000002