
    Write a function to calculate the ratio of clear routes to congested routes in a delivery network, where each route's traffic status is represented by a number, with 0 indicating normal flow and any non-zero value indicating congestion. This ratio helps fleet managers make real-time decisions about route assignments and delivery schedules.
    

    
from array import array

def zero_count(nums):
    """
    Write a function to calculate the ratio of clear routes to congested routes in a delivery network, where each route's traffic status is represented by a number, with 0 indicating normal flow and any non-zero value indicating congestion. This ratio helps fleet managers make real-time decisions about route assignments and delivery schedules.
    

    """
from array import array

def zero_count(nums):
    """
    Write a function to calculate the ratio of clear routes to congested routes in a delivery network, where each route's traffic status is represented by a number, with 0 indicating normal flow and any non-zero value indicating congestion. This ratio helps fleet managers make real-time decisions about route assignments and delivery schedules.
    

    """
    n = len(nums)
    n1 = 0
    for x in nums:
        if x == 0:
            n1 += 1
        else:
            None
    return n1 / (n - n1)