Did you just use the sentence “only 13 unarmed black men were shot by police”? That’s still outrageous. For context in the same year the UK police had 13 occasions total where officers fired their weapons, resulting in 3 fatalities. (https://www.statista.com/statistics/319246/police-fatal-shoo...)
I said “only” in relation to the myth that hundreds of unarmed black men were being shot by the police. I’m not saying 13 is good, but it’s objectively better than more than 13. There was a poll some months ago, which I can’t find, that asked people with different political beliefs to estimate how many unarmed black men were killed by police in the previous year and the liberal and progressive left had outrageous numbers. These are the same people watching the mainstream media constantly pushing the narrative that it’s open season on black men.
Yes the UK police might be better than the US police. Without knowing how many unarmed men of other ethnicities suffered the same fate (and the frequency of the respective ethnicities), it's a meaningless number. It could be "only 13 unarmed black men" because it isn't unusual for the US police to shoot unarmed men.
On second thoughts, I guess you're right: it doesn't make sense to use the quantifier "only 13" without knowing all the other numbers. This might be trivializing the matter.