condition mean min max ZT0-3 13.023279 13.023279 13.023279 ZT4-7 11.954197 11.954197 11.954197 ZT8-11 10.732523 10.732523 10.732523 ZT12-15 11.1847465 11.1847465 11.1847465 ZT16-19 10.0750355 10.0750355 10.0750355 ZT20-23 10.8337155 10.8337155 10.8337155