IMAS 2013–2014 Junior Division — Round 2 Question 1

When the digits 0, 1, 2, 5, 6, 8 and 9 are rotated $180^\circ$, they become 0, 1, 2, 5, 9, 8 and 6 respectively. What does 9105 become when the four-digit number is rotated $180^\circ$?