condition mean min max ZT0-3 17.7464 14.95215 20.54065 ZT4-7 8.952755 8.952755 8.952755 ZT8-11 14.1672 14.1672 14.1672 ZT12-15 0 0 0 ZT16-19 24.6953 24.6953 24.6953 ZT20-23 15.664649999999998 15.664649999999998 15.664649999999998