condition mean min max ZT0-3 20.4433 20.4433 20.4433 ZT4-7 17.6539 17.6539 17.6539 ZT8-11 16.820149999999998 16.820149999999998 16.820149999999998 ZT12-15 17.20815 17.20815 17.20815 ZT16-19 21.82205 21.82205 21.82205 ZT20-23 19.02265 19.02265 19.02265