chart data result problems not displaying accurately

Hi, I was wondering if someone could help. I am creating weather charts showing average low and high temperatures for different areas. I created the first chart on the 1st page, copied the data for the 2nd page, etc and just amended the target areas.

The problem I am having is that on some of the pages the difference in temperatures shows as a huge gap and on others its where it should be. I have attached the file so you can see what I am talking about, for example if you check the tab for Sri Lanka and compare with the tab for Maldives. The Sri Lanka page shows the information they way I want it to be shown.

Does anyone have any ideas how this can be solved??

Thanks,
Cheryl