How to autopopulate an if/elif block from a list of values?

I am working on a function that allows a user to provide a list of values which will then autopopulate an if/elif block. For example, here is an example of the if/elif block that I am trying to autopopulate with acres_list:

acres_list = [15, 20, 25, 35, 45]

if acres <= 15:
    return 1
elif 20 >= acres >15:
    return 2
elif 25 >= acres > 20:
    return 3       
elif 35 >= acres > 25:
    return 4     
elif 45 >= acres > 35:
    return 5     
elif acres > 45:
    return 6     

I could provide a pointer to a specific list value like so:

acres = 17.46 # Some value to test. The function should return `2`
acres_list = [15, 20, 25, 35, 45]
    
def find_acres(acres, acres_list):
    if acres <= acres_list[0]:
        return 1
    elif acres_list[1] >= acres >acres_list[0]:
        return 2
    elif acres_list[2] >= acres > acres_list[1]:
        return 3       
    elif acres_list[3] >= acres > acres_list[2]:
        return 4     
    elif acres_list[4] >= acres > acres_list[3]:
        return 5     
    elif acres > acres_list[4]:
        return 6     

However, this would fail if the user provided a list such as:

acres_list = [15, 20, 25, 35, 45, 50, 60, 70, 120]

or

acres_list = [5, 10, 15]

What approach can I take to autopopulate an if/else block with a variable sized list of values?