condition mean min max ZT0-3 11.62424 11.62424 11.62424 ZT4-7 9.97311 9.97311 9.97311 ZT8-11 8.13127 8.13127 8.13127 ZT12-15 8.790445 8.790445 8.790445 ZT16-19 17.29355 17.29355 17.29355 ZT20-23 15.4375 15.4375 15.4375