Varying the stimulus according to the number of mouse click

In my current code, there is a list of numbers called list1. And there is a polygon on the bottom of the screen. Here’s what I want: The first time a polygon is clicked, the first number of list1 appears on the screen. It’s not until I click the mouse a second time that the number becomes the second element in the list, and so on. My question is that, No matter how many times I click, the first number stays the same and the second number of list2 never appears. Here’s my code in EACH FRAME:
if mouse.isPressedIn(polygon):
click_times = mouse.clicked_name.count(“polygon”)
stimulus = list1[click_times]

Would you please tell me what I’m wrong with, and I’d appreciate any help.