For the last 12 months, it has been one of the reasons why your score is not as high as it could be. But if you have never seen it before, it probably means that other reason codes were bigger sources of score penalty than it was.
If you have a three year lease (reasonable guess) then you still owe the majority of it, which means it is causing you to lose scoring points. In the last three months of the lease you will have paid off 90% of the loan and then that reason code will definitely go away.
As you get closer to paying it off (last four months) figure out whether you expect to have no open installment accounts all once it pays off (i.e. you won't buy or lease another car right away, etc.). If so, we can suggest a method to hang on to all those scoring points you'll have, points you will lose when it pays off. The method won't help you now, but will help you then.
PS. When you say that the auto lease is your only loan right now, has it been your only loan for the last 12 months? In other words, you haven't paid off any loans recently, have you?
