Monaco is correct, while some will say their systems don't leak down, they are few and far between. What you show as the amount of leak down is well within acceptable limits. Having drove commercially for 20+ years I can say that every truck I drove would leak down at least 50% over night. The Federal Department of Transportation seta a limit of leak down with the brakes applies at 5 lbs. in 2 minutes or less as acceptable.
2012 Journey 40U (Our Incredible Journey)
2008 Dodge Dakota
2004 Subaru Baja