condition mean min max ZT0-3 6.634495358500001 6.573982741 6.695007976000001 ZT4-7 5.3831949022500005 4.611665907000001 6.1547238975 ZT8-11 9.57450146 7.38603155 11.762971369999999 ZT12-15 9.703826703499999 8.826339576999999 10.581313830000001 ZT16-19 4.865265187 4.454132771 5.2763976029999995 ZT20-23 6.89181343675 6.447064791999999 7.3365620815