condition mean min max ZT0-3 11.123534 11.123534 11.123534 ZT4-7 11.5397745 11.5397745 11.5397745 ZT8-11 10.7634255 10.7634255 10.7634255 ZT12-15 11.342613499999999 11.342613499999999 11.342613499999999 ZT16-19 10.6323995 10.6323995 10.6323995 ZT20-23 9.822607 9.822607 9.822607