condition mean min max ZT0-3 8.02232732325 7.0531608225 8.991493823999999 ZT4-7 5.0341531525 4.654519122 5.413787183 ZT8-11 5.5295677915 4.8511925300000005 6.207943052999999 ZT12-15 7.04147636725 6.2906129905 7.7923397439999995 ZT16-19 10.0287742585 8.155258729 11.902289788000001 ZT20-23 15.279429579999999 13.67779472 16.88106444