condition mean min max ZT0-3 6.52632 6.329090000000001 6.72355 ZT4-7 6.23808 6.23808 6.23808 ZT8-11 10.85255 10.85255 10.85255 ZT12-15 0 0 0 ZT16-19 10.8036 10.8036 10.8036 ZT20-23 7.971255 7.971255 7.971255