Hey there!
You can really use your common sense to figure this one out! :)
If a country is a developed, it has a lot under control! They have a lot of water, electricity, food, shelter, education, and healthcare available. If one has a health problem, there will be more advanced medicine and healthcare to help them out. There are also many other things available that help you to be healthier such as food and water availability, shelter, supplements, medicines, prescriptions, and more.
If a country is developing, it will not have all of these things ready or at the level as other countries. Therefore, it is harder to maintain good health, which will most likely lead to more health-related deaths. Many graphs, charts, and data that the WHO provides can help back this up.
Therefore, there will be more health related deaths in developing countries.
I hope that this helps!