condition mean min max ZT0-3 18.536074999999997 16.34745 20.7247 ZT4-7 17.1186 17.1186 17.1186 ZT8-11 18.24295 18.24295 18.24295 ZT12-15 0 0 0 ZT16-19 25.315849999999998 25.315849999999998 25.315849999999998 ZT20-23 25.1328 25.1328 25.1328