condition mean min max ZT0-3 6.250219518416667 5.308179995333333 7.192259041500001 ZT4-7 6.915117796500001 6.276951189 7.553284404 ZT8-11 9.3252603395 8.327413804666666 10.323106874333334 ZT12-15 9.9907050355 9.493458626999999 10.487951444 ZT16-19 10.590953314 9.959740281333334 11.222166346666667 ZT20-23 8.676477576833333 7.995338191666666 9.357616962