condition mean min max ZT0-3 4.15724 3.28686 5.161474999999999 ZT4-7 2.09847 2.09847 2.09847 ZT8-11 2.8803650000000003 2.8803650000000003 2.8803650000000003 ZT12-15 3.6942399999999997 3.625825 3.762655 ZT16-19 5.239775 5.239775 5.239775 ZT20-23 5.55772 5.55772 5.55772