Domain Authority Question

Guys,

I have a site that ranks top 10 for every keyword it targets. When the site started, i have an info graphic that was shared on pintrest like 10k times. And the site has about 50 decent links going to it from avg domains. When i go to moz and put in my domain it shows my domain authority is only 14!!!! WTF. How can i rank for 10k a month terms and only have a DA of 14? The site has over 150 ranked pages, so i would consider it an authority site in the niche. and my next question, how…

Domain Authority Question