I'm a little suspect of any claims or numbers outside of murder counts nowadays. Unreported crime was an issue before but now that police have embraced a sort of slacker/work-to-rule/soft-strike attitude to their jobs since they don't feel appreciated after civilians dared to protest their bad behavior, there's a feedback loop of: crime happens, cops are called, nothing is done, another crime happens, no one bothers to report it. It's not just the cops that are a problem either, the revolving door where criminals that do get brought in are right back out on bail is demoralizing cops and civilians alike. If real crime rates were decreasing, wouldn't we see the system that handles them also improving? Instead it looks like a shit show, thus the numbers are probably kinda bullshit.