condition mean min max ZT0-3 228.65374431499998 143.66905693 313.63843169999996 ZT4-7 48.724165774999996 41.376691629999996 56.071639919999996 ZT8-11 31.793022807499998 29.947326689999997 33.638718925 ZT12-15 15.72245708775 8.926864096 22.5180500795 ZT16-19 13.98716547 11.2686742 16.705656740000002 ZT20-23 21.5635181825 19.660108035 23.466928330000002