condition mean min max ZT0-3 2.1003475 2.09776 2.102935 ZT4-7 3.515025 3.515025 3.515025 ZT8-11 5.580695 5.580695 5.580695 ZT12-15 0 0 0 ZT16-19 2.78343 2.78343 2.78343 ZT20-23 3.5220700000000003 3.5220700000000003 3.5220700000000003