## 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!

ee/clickhouse/sql/retention/retention.py
RETENTION_SQL = """
SELECT
    datediff(%(period)s, {trunc_func}(toDateTime(%(start_date)s)), reference_event.event_date) as base_interval,
    datediff(%(period)s, reference_event.event_date, {trunc_func}(toDateTime(event_date))) as intervals_from_base,
    COUNT(DISTINCT event.person_id) count
FROM (
    SELECT 
    timestamp AS event_date,
    pdi.person_id as person_id,
    e.uuid as uuid,
    e.event as event
    FROM events e join (SELECT person_id, distinct_id FROM person_distinct_id WHERE team_id = %(team_id)s) pdi on e.distinct_id = pdi.distinct_id
    where toDateTime(e.timestamp) >= toDateTime(%(start_date)s) AND toDateTime(e.timestamp) <= toDateTime(%(end_date)s)
    AND e.team_id = %(team_id)s {returning_query} {filters}
) event
JOIN (
    {reference_event_sql}
) reference_event
    ON (event.person_id = reference_event.person_id)
WHERE {trunc_func}(event.event_date) > {trunc_func}(reference_event.event_date)
GROUP BY base_interval, intervals_from_base
ORDER BY base_interval, intervals_from_base
"""
REFERENCE_EVENT_SQL = """
SELECT DISTINCT 
{trunc_func}(e.timestamp) as event_date,
pdi.person_id as person_id,
e.uuid as uuid,
e.event as event
from events e JOIN (SELECT person_id, distinct_id FROM person_distinct_id WHERE team_id = %(team_id)s) pdi on e.distinct_id = pdi.distinct_id