This changes all the time. The union puts out a market planning podcast, the most recent one shows 6 mos to a line and yes it's the shortest at this time. Last month 9 mos was the most junior line in IND, it was the shortest but only by a month or two over a couple others.
On a month to month basis, it has a lot to do with the amount of total flying. We're probably at the end of the summer rush and in the short lull before holiday flying.