condition mean min max ZT0-3 6.54075 6.54075 6.54075 ZT4-7 6.229825 6.229825 6.229825 ZT8-11 5.7943 5.7943 5.7943 ZT12-15 6.015700000000001 6.015700000000001 6.015700000000001 ZT16-19 6.3929 6.3929 6.3929 ZT20-23 6.46767 6.46767 6.46767