County Hummingbird Population

I have noticed a big shift in the mix of hummingbirds around the county this year.  About 2 years ago my yard became overrun with Allen's, I live in an area that was almost all Anna's before this.  This year almost all the Allen's are gone, a big change from last year and the year before.  I have also observed this same phenomenon around Imperial Beach, and in the Bird and Butterfly area at the TJ river valley, and at the sunset ballfields.  

 

Was there a big explosion of Allen's around the county that now has almost completely died off?  I'm not seeing hardly any Allen's anywhere.

 

-Roger Uzun

Poway CA (near Iron Mountain)