condition mean min max ZT0-3 8.308455 7.42895 9.409405 ZT4-7 6.56634 6.56634 6.56634 ZT8-11 10.771709999999999 10.771709999999999 10.771709999999999 ZT12-15 20.166625 17.9555 22.37775 ZT16-19 16.067549999999997 16.067549999999997 16.067549999999997 ZT20-23 12.992550000000001 12.992550000000001 12.992550000000001