Consider the following statements about Indo-Tibetan Border Police (ITBP):
1) ITBP was raised in 1962.
2) ITBP is basically a mountain raised force.
3) ITBP replaced Assam rifles in Sikkim and Arunachal Pradesh in 2004-05 for border guarding duty.
4) ITBP presently has 52 service battalions.
Which of the statements given above are correct?