condition mean min max ZT0-3 1.1931800000000001 1.1931800000000001 1.1931800000000001 ZT4-7 4.904535 4.904535 4.904535 ZT8-11 2.87079 2.87079 2.87079 ZT12-15 2.37534 2.37534 2.37534 ZT16-19 1.98186 1.98186 1.98186 ZT20-23 2.3229312533333335 2.3229312533333335 2.3229312533333335