condition mean min max ZT0-3 2.5207800000000002 2.5207800000000002 2.5207800000000002 ZT4-7 1.6197599999999999 1.6197599999999999 1.6197599999999999 ZT8-11 2.39641 2.39641 2.39641 ZT12-15 2.99037 2.99037 2.99037 ZT16-19 2.739675 2.739675 2.739675 ZT20-23 2.88191 2.88191 2.88191