condition mean min max ZT0-3 14.577886 14.577886 14.577886 ZT4-7 15.520248 15.520248 15.520248 ZT8-11 14.572466 14.572466 14.572466 ZT12-15 14.577886 14.577886 14.577886 ZT16-19 14.319592 14.319592 14.319592 ZT20-23 14.5862505 14.5862505 14.5862505