condition mean min max ZT0-3 13.702985 8.028155 18.22215 ZT4-7 10.38675 10.38675 10.38675 ZT8-11 9.414305 9.414305 9.414305 ZT12-15 14.205325 13.388300000000001 15.02235 ZT16-19 16.50375 16.50375 16.50375 ZT20-23 17.4518 17.4518 17.4518