condition mean min max ZT0-3 6.068665 2.856055 7.84074 ZT4-7 1.7698749999999999 1.7698749999999999 1.7698749999999999 ZT8-11 2.93124 2.93124 2.93124 ZT12-15 4.4318124999999995 4.3666599999999995 4.496964999999999 ZT16-19 5.3715150000000005 5.3715150000000005 5.3715150000000005 ZT20-23 7.354385 7.354385 7.354385