same as mine up here in alamo! exactly 9.0 here too...and i measured rain water as low as 5.0 this past winter. it's not the norm as it is usually around 6.0...

but i don't mix regularly. too much work and wouldn't fit into the auto-sprinkler system when i'm away so i just acidify the soil a bit. like shoot for a 5-5.5 then let the tap water run for a month before adjusting again. not too scientific, i know but it fits into my K.i.s.s. system better...