The problems actually go even deeper than this. It's pretty difficult to make reasonable comparisons using crime data, even when looking across entire regions.
To illustrate this, imagine one region where the baseline crime rate is not extreme, but above average all across the region. Now, think of another place where most of the region is pretty safe, but one pocket of the area has an extremely high rate.
These two regions might have identical crime rates. But which one would you rather live in?
This is why the FBI recommends against using its own numbers to make comparisons like the grandparent's:
"Each year when Crime in the United States is published, many entities—news media, tourism agencies, and other groups with an interest in crime in our Nation—use reported figures to compile rankings of cities and counties. These rankings, however, are merely a quick choice made by the data user; they provide no insight into the many variables that mold the crime in a particular town, city, county, state, region, or other jurisdiction. Consequently, these rankings lead to simplistic and/or incomplete analyses that often create misleading perceptions adversely affecting cities and counties, along with their residents."
To illustrate this, imagine one region where the baseline crime rate is not extreme, but above average all across the region. Now, think of another place where most of the region is pretty safe, but one pocket of the area has an extremely high rate.
These two regions might have identical crime rates. But which one would you rather live in?
This is why the FBI recommends against using its own numbers to make comparisons like the grandparent's:
"Each year when Crime in the United States is published, many entities—news media, tourism agencies, and other groups with an interest in crime in our Nation—use reported figures to compile rankings of cities and counties. These rankings, however, are merely a quick choice made by the data user; they provide no insight into the many variables that mold the crime in a particular town, city, county, state, region, or other jurisdiction. Consequently, these rankings lead to simplistic and/or incomplete analyses that often create misleading perceptions adversely affecting cities and counties, along with their residents."
Source: https://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2010/...