condition mean min max ZT0-3 4.81441 3.887355 5.741465 ZT4-7 9.732515 9.732515 9.732515 ZT8-11 23.1996 23.1996 23.1996 ZT12-15 0 0 0 ZT16-19 14.51485 14.51485 14.51485 ZT20-23 12.287749999999999 12.287749999999999 12.287749999999999