condition mean min max ZT0-3 3.33831 2.952715 3.7239050000000002 ZT4-7 5.676545 5.676545 5.676545 ZT8-11 4.01898 4.01898 4.01898 ZT12-15 0 0 0 ZT16-19 4.642860000000001 4.642860000000001 4.642860000000001 ZT20-23 6.65415 6.65415 6.65415