condition mean min max ZT0-3 7.096970000000001 7.01701 7.1769300000000005 ZT4-7 5.75262 5.75262 5.75262 ZT8-11 5.972295 5.972295 5.972295 ZT12-15 0 0 0 ZT16-19 6.351445 6.351445 6.351445 ZT20-23 7.84674 7.84674 7.84674