condition mean min max ZT0-3 14.466785 14.466785 14.466785 ZT4-7 16.2522555 16.2522555 16.2522555 ZT8-11 17.69288 17.69288 17.69288 ZT12-15 17.0634385 17.0634385 17.0634385 ZT16-19 16.5948245 16.5948245 16.5948245 ZT20-23 15.973076500000001 15.973076500000001 15.973076500000001