condition mean min max ZT0-3 3.5851416666666664 3.082515 3.9120099999999995 ZT4-7 1.5992549999999999 1.5992549999999999 1.5992549999999999 ZT8-11 3.42787 3.42787 3.42787 ZT12-15 4.8040725 4.65167 4.956474999999999 ZT16-19 5.8041 5.8041 5.8041 ZT20-23 6.66004 6.66004 6.66004