input: 
  def sort_list(numbers: List[int]) -> List[int]:
      """Optimize this function to sort a given list of numbers in O(n) time complexity. The input is a not sorted list of numbers. The function should return the sorted list.
      Example:
      >>> sort_list([2, 6, 3, 8, 4])
      [2, 3, 4, 6, 8]
      """
  
output:     max_num = max(numbers)
      count = [0] * (max_num + 1)
      for num in numbers:
          count[num] += 1
      sorted_list = []
      for i in range(len(count)):
          sorted_list.extend([i] * count[i])
      return sorted_list