Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
How many classes between senior and junior year for world history

### Inputs:
table_name: table, columns: ['SUBJECT', 'FRESHMAN (Grade 7)', 'SOPHOMORE (Grade 8)', 'JUNIOR (3rd Year)', 'SENIOR (4th Year)']

### Response:
SELECT COUNT SENIOR (4th Year) FROM table WHERE JUNIOR (3rd Year) = World History