condition mean min max ZT0-3 1.0236026666666667 0.431688 1.47353 ZT4-7 0.386093 0.386093 0.386093 ZT8-11 0.1323645 0.1323645 0.1323645 ZT12-15 2.37799 1.503875 3.2521050000000002 ZT16-19 1.47753 1.47753 1.47753 ZT20-23 1.261476 1.261476 1.261476