condition mean min max ZT0-3 6.084155 4.7068449999999995 7.4614650000000005 ZT4-7 3.485335 3.485335 3.485335 ZT8-11 1.767125 1.767125 1.767125 ZT12-15 0 0 0 ZT16-19 1.3456000000000001 1.3456000000000001 1.3456000000000001 ZT20-23 2.79365 2.79365 2.79365