condition mean min max ZT0-3 4.1846 3.305435 5.063765 ZT4-7 4.6573150000000005 4.6573150000000005 4.6573150000000005 ZT8-11 5.6833849999999995 5.6833849999999995 5.6833849999999995 ZT12-15 0 0 0 ZT16-19 6.502855 6.502855 6.502855 ZT20-23 6.47045 6.47045 6.47045