<p>Table: <code>Project</code></p> <pre> +-------------+---------+ | Column Name | Type | +-------------+---------+ | project_id | int | | employee_id | int | +-------------+---------+ (project_id, employee_id) is the primary key of this table. employee_id is a foreign key to <code>Employee</code> table. Each row of this table indicates that the employee with employee_id is working on the project with project_id. </pre> <p> </p> <p>Table: <code>Employee</code></p> <pre> +------------------+---------+ | Column Name | Type | +------------------+---------+ | employee_id | int | | name | varchar | | experience_years | int | +------------------+---------+ employee_id is the primary key of this table. It's guaranteed that experience_years is not NULL. Each row of this table contains information about one employee. </pre> <p> </p> <p>Write an SQL query that reports the <strong>average</strong> experience years of all the employees for each project, <strong>rounded to 2 digits</strong>.</p> <p>Return the result table in <strong>any order</strong>.</p> <p>The query result format is in the following example.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> Project table: +-------------+-------------+ | project_id | employee_id | +-------------+-------------+ | 1 | 1 | | 1 | 2 | | 1 | 3 | | 2 | 1 | | 2 | 4 | +-------------+-------------+ Employee table: +-------------+--------+------------------+ | employee_id | name | experience_years | +-------------+--------+------------------+ | 1 | Khaled | 3 | | 2 | Ali | 2 | | 3 | John | 1 | | 4 | Doe | 2 | +-------------+--------+------------------+ <strong>Output:</strong> +-------------+---------------+ | project_id | average_years | +-------------+---------------+ | 1 | 2.00 | | 2 | 2.50 | +-------------+---------------+ <strong>Explanation:</strong> The average experience years for the first project is (3 + 2 + 1) / 3 = 2.00 and for the second project is (3 + 2) / 2 = 2.50 </pre>