condition mean min max ZT0-3 18.095983 18.095983 18.095983 ZT4-7 17.349502 17.349502 17.349502 ZT8-11 16.131325 16.131325 16.131325 ZT12-15 14.7960095 14.7960095 14.7960095 ZT16-19 14.8134385 14.8134385 14.8134385 ZT20-23 12.9554385 12.9554385 12.9554385