condition mean min max ZT0-3 1.115621 1.115621 1.115621 ZT4-7 1.2919835000000002 1.2919835000000002 1.2919835000000002 ZT8-11 1.5232515 1.5232515 1.5232515 ZT12-15 2.84638 2.84638 2.84638 ZT16-19 2.01119 2.01119 2.01119 ZT20-23 1.867945 1.867945 1.867945