condition mean min max ZT0-3 6.946806666666666 5.308 8.07352 ZT4-7 7.5788 7.5788 7.5788 ZT8-11 17.93485 17.93485 17.93485 ZT12-15 7.8986275 5.33521 10.462045 ZT16-19 0.0 0.0 0.0 ZT20-23 8.38955 8.38955 8.38955