condition mean min max ZT0-3 23.609398 23.609398 23.609398 ZT4-7 23.127381 23.127381 23.127381 ZT8-11 22.277104 22.277104 22.277104 ZT12-15 17.658746 17.658746 17.658746 ZT16-19 22.0729265 22.0729265 22.0729265 ZT20-23 23.106224 23.106224 23.106224