condition mean min max ZT0-3 0.5433712742166666 0.4181745 0.73968419345 ZT4-7 0.4094435 0.4094435 0.4094435 ZT8-11 1.050562 1.050562 1.050562 ZT12-15 0.42846813525000005 0.38318604500000003 0.4737502255 ZT16-19 0.6373635 0.6373635 0.6373635 ZT20-23 1.3735355 1.3735355 1.3735355