condition mean min max ZT0-3 6.7626797629999995 6.474267770999999 7.051091755 ZT4-7 7.180531564000001 7.1188331620000005 7.242229966 ZT8-11 6.784803824999999 5.848628782 7.7209788679999996 ZT12-15 7.387740701833334 7.171394052 7.604087351666667 ZT16-19 8.684691831666667 8.487683121333333 8.881700542 ZT20-23 10.391679280999998 9.975893364666666 10.807465197333332