What are the top ~10-20 most popular items across all formats and pokemon?

I'm just curious. Across all formats (although OU and VGC probably cover pretty much everything) what are the most common held items?

I know you can look up data on specific pokemon on sites like trainer tower (i.e. for VGC in May, Kartana's most popular held items were Grassium Z [35%], Focus Sash [19%], and Choice Scarf [15%]) but I'm interested in these numbers across all formats and pokemon. Not sure if there's a way to easily find this information or not.

I think for the sake of reducing redundancy, all Z Crystals should be considered a single "item" and all Mega Stones should be considered a single "item" (I've grouped a few other items together as well). I'm thinking the ranking might look something like the following, but I'm interested in others' opinions/predictions and in any actual hard data that's available.

(After the top 10 it gets pretty questionable.)

1. Mega Stone

2. Z Crystal

3. Leftovers

4. Choice Scarf

5. Life Orb

6. Focus Sash

7. Assault Vest

8. Choice Band

9. Choice Specs

10. Sitrus Berry

11. Eviolite

12. Lum Berry

13. Damage-reducing berry family

14. Figy Berry family

15. Mental Herb

16. Weakness Policy

17. Rocky Helmet

18. Expert Belt

19. Black Sludge

20. Flame Orb