condition mean min max ZT0-3 7.265043333333333 3.5414 9.388015 ZT4-7 4.19165 4.19165 4.19165 ZT8-11 4.676195 4.676195 4.676195 ZT12-15 6.2937325 5.886645 6.70082 ZT16-19 8.68721 8.68721 8.68721 ZT20-23 9.8098 9.8098 9.8098