With reference to the recommendations of the 15th Finance Commission, consider the following statements:

1. It recommended a specific-purpose grant for the school education sector.

2. It recommended that States' share in the divisible pool of central taxes be reduced compared to the 14th Finance Commission's recommendation.

3. It included agricultural performance as one criterion for horizontal tax devolution among States.

4. It included 'tax effort' as one of the criteria for horizontal devolution.

How many of the above statements are correct?