Never look for the avg. always aim for the max points. I believe the max mile run is 5:30 for guys.
What you should do is continue practicing the PFT. in all types of weather and following their regs for the break periods. Running is only one part of the PFT.
You should also do it at the wee hours of the morning, because some cadets perform lower due to exhaustion... in other words go to bed at your normal time and wake up about 5:30.