That's some really overly simplistic thinking about proportionality or disproportionality. Women are under-arrested per-capita, but we don't think police are uniformly sexist against men. We don't get worried that elderly americans, or Asian Americans, or Amish/mennonite/devout Muslim or orthodox Jewish americans are all arrested at levels FAR BELOW their raw per-capita numbers in the country. We don't accuse or assume that the police have massive hidden pro-women or pro-elderly or pro-Asian or Pro-religion biases to explain why so few people from those groups are arrested, assaulted by, or killed by police. We understand that it's silly to expect police interactions and police violence to be distributed equally (what current social justice proponents would call "equity") across a society with massively unequal crime rates.
If you compare the numbers of people from "x" group who are killed by police annually to the number of annual violent crimes, or arrests for violent crimes, or simply number of murders and assaults committed each year by people from "X" group, you find an extremely high correlation and close proportionality.
People over age 60 or women or Asian-Americans aren't committing murders, aren't encountering police in violent situations, and aren't getting arrested or killed. P
eople from other groups (and basically just males from age 15-40 without stable employment or families) are doing all of those bad things, and are getting arrested and killed.
The 72% total groups hispanics with whites. I personally think all these categories are a stupid antiquated dead-end, but
"white" americans make up 60% of the country, not 72%.