What regions offer the best ROI for landlords?

Looking at the top 10 and the bottom 10, it would imply that the cheaper the property the better the ROI. For me it would be interesting to plot this alongside property price variation.

https://www.propertyinvestortoday.co.uk/breaking-news/2021/4/revealed-where-is-the-most-profitable-place-to-buy-uk-investment-property