First, for people who are unclear about the term "clearance rate"... I found this definition on Google: "charge being laid" (someone was charged with a crime).
Second, as I understand burglary, it is a property crime, like breaking & entering into a home, business, or car. Robbery is person-to-person theft (stick-up by knife, gun, etc.) If we think about burglary for a moment, most burglaries happen when no one is around. Thus, imagine how difficult it is to have enough evidence to even lay a charge against someone. Vanishingly small. I'm not sure that is a good way to judge the effectiveness of police. I lived in an apartment building many years ago where someone got to the roof, then entered an open window and stole some things. The chances of catching this person are incredibly low. The police came to our building to ask questions and look at the inside of various apartments. The effort was made, but it would be nearly impossible to lay charges with so little tangible evidence.
Third, think about robbery. When I think about robbery, I think about "wrong place, wrong time" -- on a street alone at night. What are the chances the police will be able to gather enough evidence to lay a charge? Again, vanishingly small.
Lastly, about this clearance rate for these two crime categories: How does it compare to other high income countries like Canada, UK, France, Netherlands, Germany, Korea, Taiwan, Japan, etc.? I'm sure it is also fairly low.