sector exploration

[ChickenHawk07]

I just did a full sweep of my sector but the exploration still shows it as 99%
Now is this normal or can you have 100%?
Also, I don't think I missed any sectors, but if I did miss one it seams to be impossible to tell which one I miss.

It is hard to tell which have been missed, but go through and look again. The one(s) which have been missed have a very dark grey dot in the middle. Hard to see, but they are there.

[ChickenHawk07]

There are 625 sectors per Galaxy. If you go to the Diplomacy section where you can message people and change Status, you can highlight yourself and click on Details. In your exploration section it will tell you how many sectors you have explored. You will probably find you are a few short of 625.