condition mean min max ZT0-3 5.365855 5.365855 5.365855 ZT4-7 5.39716 5.39716 5.39716 ZT8-11 5.357855 5.357855 5.357855 ZT12-15 7.088150000000001 7.088150000000001 7.088150000000001 ZT16-19 6.08317 6.08317 6.08317 ZT20-23 5.950115 5.950115 5.950115