## Bug description

*Please describe.*  
- some datapoints show 0 but people will appear in modal

*If this affects the front-end, screenshots would be of great help.*  

## Expected behavior
- amount of people and datapoint should be the same


## How to reproduce

1. demo data clickhouse instance
2. go to retention trends for a day with some people


## Environment

- [ ] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context



#### *Thank you* for your bug report – we love squashing them!

posthog/queries/test/test_retention.py
result = retention().run(
                RetentionFilter(data={"date_to": self._date(10, hour=6), "display": TRENDS_LINEAR}), self.team
            )
            self.assertEqual(
                result[0]["count"], 2,
            )
            self.assertEqual(
                result[0]["labels"],
                ["Day 0", "Day 1", "Day 2", "Day 3", "Day 4", "Day 5", "Day 6", "Day 7", "Day 8", "Day 9", "Day 10"],
            )
            self.assertEqual(
                result[0]["days"],
                [
                    "2020-06-10",
                    "2020-06-11",
                    "2020-06-12",
                    "2020-06-13",
                    "2020-06-14",
                    "2020-06-15",
                    "2020-06-16",
                    "2020-06-17",
                    "2020-06-18",
                    "2020-06-19",
                    "2020-06-20",
                ],
            )
            self.assertEqual(
                result[0]["data"], [100.0, 100.0, 100.0, 50.0, 0.0, 50.0, 100.0, 0.0, 0.0, 0.0, 0.0],
            )
        def test_first_time_retention(self):