You are given clinic-level device status events and need to identify the clinics with the worst reliability over the last 30 days. Write a PostgreSQL query that returns the top 10% of clinics by device offline rate, where offline rate is defined as offline events divided by total device status events in the 30-day window.
| Column | Type | Description |
|---|---|---|
| clinic_idPK | INT | Primary key for the clinic |
| clinic_name | VARCHAR(255) | Human-readable clinic name |
| Column | Type | Description |
|---|---|---|
| event_idPK | INT | Primary key for the device event |
| clinic_id | INT | Clinic associated with the event |
| device_id | INT | Device identifier |
| event_ts | TIMESTAMP | Timestamp when the device status event occurred |
| event_type | VARCHAR(50) | Device status event type |