You need to optimize a Python program for faster performance.
def sort_number(arr):
    for i in range(len(arr)):
        for j in range(i + 1, len(arr)):
            if arr[i] > arr[j]:
                temp = arr[i]
                arr[i] = arr[j]
                arr[j] = temp
def sort_number(arr):
    arr.sort()