I believe I have a hack for this. What I did was to create two assertions for the same property. One assertion test that the property count is greater than zero and I created another assertion that test that the property is greater than or equal to the value I expect. Therefore, if the property is empty or zero then the first assertion that test if the property is greater than zero fails and that gives an indication that something is not right.
This may be a hack but until there is a better way of asserting a range of counts, the test is robust enough.