condition mean min max ZT0-3 5.580347370666667 3.263633414 7.897061327333333 ZT4-7 8.906920114999998 8.334745167 9.479095062999999 ZT8-11 9.7389961145 9.047503111 10.430489118 ZT12-15 8.758271233166667 8.623530897 8.893011569333334 ZT16-19 9.979533914833333 9.606670896 10.352396933666666 ZT20-23 9.413249092333334 9.147457226 9.679040958666667