input: Write a function to make the provided Python code snippet more efficient. The function should determine the commission rate based on the value of gross_sales. If gross_sales is greater than or equal to 10000, the commission rate should be 0.1. If gross_sales is between 5000 and 10000, the commission rate should be 0.07. If gross_sales is less than 5000, the commission rate should be 0.05.
  def determine_commission_rate(gross_sales):
      if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.05
  assert determine_commission_rate(15000) == 0.1
  assert determine_commission_rate(7500) == 0.07
  assert determine_commission_rate(4000) == 0.05
  assert determine_commission_rate(10000) == 0.1
  assert determine_commission_rate(5000) == 0.07
output: def determine_commission_rate(gross_sales):
      if gross_sales >= 10000:
          return 0.1
      elif gross_sales >= 5000:
          return 0.07
      else:
          return 0.05