condition mean min max ZT0-3 19.246675 17.499 20.99435 ZT4-7 10.930245 10.930245 10.930245 ZT8-11 9.160599999999999 9.160599999999999 9.160599999999999 ZT12-15 0 0 0 ZT16-19 18.1599 18.1599 18.1599 ZT20-23 17.026 17.026 17.026