What is "Lost is Rank" on Adwords Report?

How do I read it... Do i want a lower % or a higher %?

Of my 19 Campaigns my Lost is Rank % ranges from 2% to 64%?

I dont see how I can be missing impressions my Avg. Position is 3 and im Lost is Budget is 0% for all of my campaigns... Can anyone help me understand this better?

Without looking at the account it is hard to tell however, I would look at a keyword level to see what is going on. although your avarage position is 3.0 this doesn't mean that all your keywords are appearing on the first page of Google. Some keywords may appear on page 3, 4 5+ and are therefore losing to rank.