## Is your feature request related to a problem?

Compare year to date
![image](https://user-images.githubusercontent.com/1727427/101010122-8044ed00-3562-11eb-8be1-8462250ef97a.png)

With last 90 days [(link)](https://app.posthog.net/insights?display=ActionsBar&events=%5B%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A0%2C%22math%22%3A%22total%22%7D%5D&shown_as=Lifecycle&actions=%5B%5D&properties=%5B%7B%22key%22%3A%22%24current_url%22%2C%22value%22%3A%22https%3A%2F%2Fposthog.com%22%2C%22operator%22%3A%22not_icontains%22%2C%22type%22%3A%22event%22%7D%2C%7B%22key%22%3A%22id%22%2C%22value%22%3A71%2C%22type%22%3A%22cohort%22%7D%5D&interval=week&date_from=-90d)
![image](https://user-images.githubusercontent.com/1727427/101010537-9f437f00-3562-11eb-8e9f-a7e75f0018f5.png)


## Describe the solution you'd like



## Describe alternatives you've considered



## Additional context



#### *Thank you* for your feature request – we love each and every one!

posthog/queries/test/test_trends.py
self._test_math_property_aggregation("avg", values=[2, 3, 5.5, 7.5], expected_value=4.5)
        def test_min_filtering(self):
            self._test_math_property_aggregation("min", values=[2, 3, 5.5, 7.5], expected_value=2)
        def test_max_filtering(self):
            self._test_math_property_aggregation("max", values=[2, 3, 5.5, 7.5], expected_value=7.5)
        def test_median_filtering(self):
            self._test_math_property_aggregation("median", values=range(101, 201), expected_value=150)
        def test_p90_filtering(self):
            self._test_math_property_aggregation("p90", values=range(101, 201), expected_value=190)
        def test_p95_filtering(self):
            self._test_math_property_aggregation("p95", values=range(101, 201), expected_value=195)
        def test_p99_filtering(self):
            self._test_math_property_aggregation("p99", values=range(101, 201), expected_value=199)
        def test_avg_filtering_non_number_resiliency(self):
            sign_up_action, person = self._create_events()
            person_factory(team_id=self.team.pk, distinct_ids=["someone_else"])
            event_factory(team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": 2})
            event_factory(team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": "x"})
            event_factory(team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": None})
            event_factory(team=self.team, event="sign up", distinct_id="someone_else", properties={"some_number": 8})
            action_response = trends().run(
                Filter(data={"actions": [{"id": sign_up_action.id, "math": "avg", "math_property": "some_number"}]}),
                self.team,
            )
            event_response = trends().run(
                Filter(data={"events": [{"id": "sign up", "math": "avg", "math_property": "some_number"}]}), self.team
            )
            self.assertEqual(action_response[0]["data"][-1], 5)
            self.assertTrue(self._compare_entity_response(action_response, event_response))
        def test_per_entity_filtering(self):