condition mean min max ZT0-3 12.358425 11.24705 13.4698 ZT4-7 19.21275 19.21275 19.21275 ZT8-11 21.902700000000003 21.902700000000003 21.902700000000003 ZT12-15 0 0 0 ZT16-19 18.405549999999998 18.405549999999998 18.405549999999998 ZT20-23 17.3215 17.3215 17.3215