condition mean min max ZT0-3 6.13084 6.13084 6.13084 ZT4-7 5.658355 5.658355 5.658355 ZT8-11 3.9316 3.9316 3.9316 ZT12-15 6.44463 6.44463 6.44463 ZT16-19 5.489475 5.489475 5.489475 ZT20-23 2.450675 2.450675 2.450675