condition mean min max ZT0-3 14.752407 14.752407 14.752407 ZT4-7 13.257586 13.257586 13.257586 ZT8-11 13.5113535 13.5113535 13.5113535 ZT12-15 12.1502935 12.1502935 12.1502935 ZT16-19 13.6208355 13.6208355 13.6208355 ZT20-23 13.8647205 13.8647205 13.8647205