condition mean min max ZT0-3 2.9069875 2.90606 2.907915 ZT4-7 2.7734199999999998 2.7734199999999998 2.7734199999999998 ZT8-11 2.997395 2.997395 2.997395 ZT12-15 0 0 0 ZT16-19 4.2749950000000005 4.2749950000000005 4.2749950000000005 ZT20-23 3.8171600000000003 3.8171600000000003 3.8171600000000003