condition mean min max ZT0-3 10.5974425 10.223335 10.97155 ZT4-7 8.52381 8.52381 8.52381 ZT8-11 4.10732 4.10732 4.10732 ZT12-15 0 0 0 ZT16-19 6.94796 6.94796 6.94796 ZT20-23 7.938295 7.938295 7.938295