condition mean min max ZT0-3 2.391925 2.391925 2.391925 ZT4-7 3.380045 3.380045 3.380045 ZT8-11 2.992 2.992 2.992 ZT12-15 0.2517555 0.2517555 0.2517555 ZT16-19 2.955365 2.955365 2.955365 ZT20-23 2.4563949999999997 2.4563949999999997 2.4563949999999997