condition mean min max ZT0-3 225.847441 225.847441 225.847441 ZT4-7 192.9345515 192.9345515 192.9345515 ZT8-11 253.53260699999998 253.53260699999998 253.53260699999998 ZT12-15 247.670438 247.670438 247.670438 ZT16-19 293.56636050000003 293.56636050000003 293.56636050000003 ZT20-23 276.3472945 276.3472945 276.3472945