How to get "public" share counts using graph API

Question

When I get the number of shares using the FB Graph API Explorer ({page-post-id}?fields=id,shares) I get:

{
  "id": "XXX_XXX",
  "shares": {
    "count": 79
  }
}

On the FB site, only shows "public" shares when we check:
(text at the bottom: "Some posts may not be displayed due to their privacy settings")

Is there any way to fetch this quantity of "public" shares using the Graph API?
Or some other way than checking manually on the FB page?