Consider the following statements about the administrative system of the Delhi Sultanate:

1. The title 'Amil' referred to the official responsible for revenue collection.

2. The Iqta system was an ancient indigenous Indian institution that already existed well before the Delhi Sultans arrived.

3. The office of 'Mir Bakshi' was created by the Khalji Sultans of Delhi.

Which of the statements given above is/are correct?