Floating point arithmetic is the bane of statistics. Golden rule: round, round round.
Occasionally while surfing you stumble upon some great examples of where statistics should be sanitized before display. Here’s an example from maps.police.uk which charts crime areas and hotspots.
Although I commend the lame effort to instil confidence in the area being “safe”, inferring that somebody has committed 0.7 of a crime is a little silly. Was it a burglary gone wrong? Someone who only beat up 70% of a pensioner? At least round it to the nearest integer, guys!