condition mean min max ZT0-3 11.538427500000001 10.016655 13.0602 ZT4-7 16.771549999999998 16.771549999999998 16.771549999999998 ZT8-11 15.151250000000001 15.151250000000001 15.151250000000001 ZT12-15 0 0 0 ZT16-19 12.574950000000001 12.574950000000001 12.574950000000001 ZT20-23 12.9714 12.9714 12.9714