Vault audit log error "permission denied" metric

Looking at the Telemetry doc (vaultproject.io/docs/internals/telemetry.html), I didn’t see any available metric that exposes errors from API such as “permission denied” errors found in vault_audit.log

I would think this would be a common metric, not sure if I’m missing it. A vault request as an example that has an error:

{
  "time": "2019-11-26T04:52:41.843304035Z",
  "type": "request",
  "auth": {
    "client_token": "hmac-sha256:c800294be75af6cd38a2595c..........",
    "accessor": "hmac-sha256:70124357345d0f6edbd204.................",
    "display_name": "approle",
    "policies": [
      "default",
      "graphcluster"
    ],
    "token_policies": [
      "default",
      "cluster"
    ],
    "metadata": {
      "role_name": "cluster"
    },
    "entity_id": "e962289b-c00e-........",
    "token_type": "service"
  },
  "request": {
    "id": "5027ffc6-bcc8-.........",
    "operation": "read",
    "client_token": "hmac-sha256:c800294be75af6cd38a2595c4c842.............",
    "client_token_accessor": "hmac-sha256:70124357345d0f6edbd204277dd26............",
    "namespace": {
      "id": "root",
      "path": ""
    },
    "path": "kv/data/null",
    "data": null,
    "policy_override": false,
    "remote_address": "x.x.x.x",
    "wrap_ttl": 0,
    "headers": {}
  },
  "error": "1 error occurred:\n\t* permission denied\n\n"
}

Is there an available metric to track this so I can setup graph visualization via graphite/grafana?