condition mean min max ZT0-3 7.9935275 7.83409 8.152965 ZT4-7 2.6744000000000003 2.6744000000000003 2.6744000000000003 ZT8-11 2.492855 2.492855 2.492855 ZT12-15 0 0 0 ZT16-19 4.26159 4.26159 4.26159 ZT20-23 3.259915 3.259915 3.259915