condition mean min max ZT0-3 16.437675 16.11835 16.756999999999998 ZT4-7 30.07815 30.07815 30.07815 ZT8-11 27.26715 27.26715 27.26715 ZT12-15 0 0 0 ZT16-19 25.8803 25.8803 25.8803 ZT20-23 22.2592 22.2592 22.2592