Given the following table schemas, how would you figure out the overall attendance rate for each grade on 2018-03-12? Answers will be provided in SQL for premium users.
Table 1: student_attendance_log
| Column Name | Data Type | Description |
|---|---|---|
| date | string | date of log per student_id, format is 'yyyy-mm-dd' |
| student_id | integer | id of the student |
| attendance_status | string | Possible values are ['present', 'tardy', 'absent'] |
Table 2: student_demographic
| Column Name | Data Type | Description |
|---|---|---|
| student_id | integer | id of the student |
| grade_level | integer | will be a value between 0-12, which corresponds |
| date_of_birth | string | Student birth date, format is 'yyyy-mm-dd' |