condition mean min max ZT0-3 6.30183 6.30183 6.30183 ZT4-7 4.27741 4.27741 4.27741 ZT8-11 5.01103 5.01103 5.01103 ZT12-15 6.10414 6.10414 6.10414 ZT16-19 8.12797 8.12797 8.12797 ZT20-23 7.29216 7.29216 7.29216