condition mean min max ZT0-3 14.970400000000001 14.8862 15.0546 ZT4-7 9.423675 9.423675 9.423675 ZT8-11 5.2239 5.2239 5.2239 ZT12-15 0 0 0 ZT16-19 9.509325 9.509325 9.509325 ZT20-23 13.5353 13.5353 13.5353