# Training Progress Review

THE GREAT DUCK MIGRATION! · challenge 16 · medium

> General Gander spreads tactical maps across the planning table. "Military precision demands clear battle plans! I need athletes who competed in 2024 AND improved in 2025. First identify 2024 participants, then cross-reference with 2025 improvements!"

## Task

Return the sum of SSNs for all ducks who competed in both 2024 and 2025, and whose overall average score improved from 2024 to 2025. Calculate the overall average by taking the mean of all their scores in that year (across all sports and all attempts combined). You will be working with `duck_athletes` and `performance_records` tables.

## Tables

### `performance_records` (800 rows)

| column | type |
| --- | --- |
| duck_id | BIGINT |
| sport | VARCHAR |
| score | DOUBLE |
| competition_date | DATE |

### `duck_athletes` (50 rows)

| column | type |
| --- | --- |
| id | BIGINT |
| ssn | BIGINT |
| name | VARCHAR |
| age | BIGINT |
| hometown | VARCHAR |

## Data

The tables live in a DuckDB database: https://dbquacks.com/data/databases/athletic_champions.duckdb

To query it outside the browser, attach it read-only:

```sql
ATTACH 'https://dbquacks.com/data/databases/athletic_champions.duckdb' AS db (READ_ONLY);
USE db;
```

Play it in the browser: https://dbquacks.com/challenges/athletic/16

## Answer

The expected answer is not published. Submit on the page to have it checked.