condition mean min max ZT0-3 6.989115 6.989115 6.989115 ZT4-7 8.932435 8.932435 8.932435 ZT8-11 8.646025 8.646025 8.646025 ZT12-15 4.761815 4.761815 4.761815 ZT16-19 4.731685 4.731685 4.731685 ZT20-23 5.72974 5.72974 5.72974