There was a 2.5 year gap between V8 (JAN2013) and V9 (APR2015) releases. However, the V9 had file time stamps of JUL2013!?! Surprisingly, V10 then appeared AUG2015. Maybe Subaru thought better of selling map files generated JUL2013 as a APR2015 release with V9. I do not know what the file time stamps for V10 are.