7 years I imagine is correct for Alaska going forward. There are 4 year upgrades right now but that is because there was a three year gap in hiring. So those hired at the beginning of the last hiring boom benefited from this situation. The new numbers that I have seen have very little growth over the next 24 months which will slow hiring and upgrades... it looks like hiring for attrition, plus 50 to 100 a year for growth