Your tests are so infrequent I'm not sure they are helping your case much. I have periods ocassionally when speed is slower but then it returns to quite good. Can't tell if there is any pattern from the way you are running tests.
I have to agree with BirdDog here... I see only one test since the 7th with the appropriate file size and maybe one or two on the day you ran the test. Is there something that compels you to the run the tests when you do? As in, do you run a speed test if you get online and feel it is slow? What device are you running the tests on? Is it wired or wireless? If wireless, what is the distance between the HughesNet Wi-Fi modem and your device? Are there other devices on the network at the same time?