condition mean min max ZT0-3 2.4936416666666665 1.7635649999999998 2.98918 ZT4-7 2.94965 2.94965 2.94965 ZT8-11 2.473255 2.473255 2.473255 ZT12-15 7.8510175 7.439885 8.26215 ZT16-19 6.616515 6.616515 6.616515 ZT20-23 4.5381350000000005 4.5381350000000005 4.5381350000000005