that *00Mbps is only the speed that your LAN connection could take at MAX.
Perhaps in *0 years we'll have some great fibre optic lines that will allow us to match that with internet speeds.
For now we get what we get, your **4kb/s is quite slow but I just tried it myself and I am also quite slow, I usually get nearer to the 2mbs I am paying for.
Try doing the test at different times when other people are unlikely to be sharing your connection, you'll see better results!