condition mean min max ZT0-3 6.8273850000000005 6.59585 7.0589200000000005 ZT4-7 7.495865 7.495865 7.495865 ZT8-11 9.596635 9.596635 9.596635 ZT12-15 0 0 0 ZT16-19 8.121815 8.121815 8.121815 ZT20-23 8.130244999999999 8.130244999999999 8.130244999999999