condition mean min max ZT0-3 18.63145 17.6048 19.658099999999997 ZT4-7 16.4889 16.4889 16.4889 ZT8-11 13.3714 13.3714 13.3714 ZT12-15 0 0 0 ZT16-19 16.2016 16.2016 16.2016 ZT20-23 17.06335 17.06335 17.06335