+-------------+---------+
| 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 Employee table.
Table: Employee
+------------------+---------+
| Column Name | Type |
+------------------+---------+
| employee\_id | int |
| name | varchar |
| experience\_years | int |
+------------------+---------+
employee\_id is the primary key of this table.
Write an SQL query that reports the average experience years of all the employees for each project, rounded to 2 digits.
The query result format is in the following example:
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 |
+-------------+--------+------------------+
Result table:
+-------------+---------------+
| project\_id | average\_years |
+-------------+---------------+
| 1 | 2.00 |
| 2 | 2.50 |
+-------------+---------------+
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