condition mean min max ZT0-3 9.772456 9.772456 9.772456 ZT4-7 9.536857000000001 9.536857000000001 9.536857000000001 ZT8-11 8.720384 8.720384 8.720384 ZT12-15 8.4950115 8.4950115 8.4950115 ZT16-19 9.187791 9.187791 9.187791 ZT20-23 8.920012 8.920012 8.920012