condition mean min max ZT0-3 32.135394 32.135394 32.135394 ZT4-7 20.728634 20.728634 20.728634 ZT8-11 15.6880945 15.6880945 15.6880945 ZT12-15 19.3681835 19.3681835 19.3681835 ZT16-19 17.1881505 17.1881505 17.1881505 ZT20-23 16.186582 16.186582 16.186582