condition mean min max ZT0-3 17.531883 17.531883 17.531883 ZT4-7 22.226562 22.226562 22.226562 ZT8-11 21.29041 21.29041 21.29041 ZT12-15 18.9271655 18.9271655 18.9271655 ZT16-19 22.6312145 22.6312145 22.6312145 ZT20-23 26.2938445 26.2938445 26.2938445