condition mean min max ZT0-3 7.74396830375 7.2841677155 8.203768892 ZT4-7 7.844647193 7.219349341 8.469945045 ZT8-11 8.982217351333333 8.522255396999999 9.442179305666667 ZT12-15 8.408578231833333 8.150836395333334 8.666320068333333 ZT16-19 9.3149545925 8.669137286 9.960771899 ZT20-23 10.184700784333334 9.756315968 10.613085600666667