condition mean min max ZT0-3 13.291517 13.291517 13.291517 ZT4-7 11.1098885 11.1098885 11.1098885 ZT8-11 11.8842435 11.8842435 11.8842435 ZT12-15 11.651256 11.651256 11.651256 ZT16-19 12.038424 12.038424 12.038424 ZT20-23 12.994221 12.994221 12.994221