condition mean min max ZT0-3 2.0959725000000002 2.08018 2.111765 ZT4-7 1.785045 1.785045 1.785045 ZT8-11 1.920485 1.920485 1.920485 ZT12-15 0 0 0 ZT16-19 2.23349 2.23349 2.23349 ZT20-23 2.5971900000000003 2.5971900000000003 2.5971900000000003