Top 10 Chocolate Bars in the UK

I have been trying to find information on the best selling chocolate bars in the UK. The only top 10 list I can find is this:

10. Snickers

9. M&M’s

8. Trident

7. Reese’s

6. Dove/Galaxy

5. Milka

4. Cadbury Dairy Milk

3. Orbit

2. Extra

1. Kit Kat

I am unsure of the reliability of the figures and indeed there are no sales figures. If anyone can help please let me know as I would like to use correct information when discussing this with my classes.