condition mean min max ZT0-3 23.48947 23.48947 23.48947 ZT4-7 23.686239 23.686239 23.686239 ZT8-11 26.130902 26.130902 26.130902 ZT12-15 18.907441 18.907441 18.907441 ZT16-19 21.973795000000003 21.973795000000003 21.973795000000003 ZT20-23 21.0999285 21.0999285 21.0999285