One criminal avoided jail despite having more than 300 offences to his name, according to details revealed under freedom of information laws.
In West Mercia, which polices Shropshire and surrounding counties, 92 per cent of offenders avoided jail at sentence, a figure of nearly 19,000. Many allowed to walk from court had a long list of previous convictions.
In Dyfed-Powys, which covers Mid Wales, 94 per cent of those found guilty, equating to nearly 10,000 criminals, walked free from court after committing offences.
Only three other police forces in the UK – Northumbria, Warwickshire and Lincolnshire – had higher percentages.
Nationally, according to the figures obtained by campaign group the Centre for Crime Prevention, in 2012 some 76,802 criminals found guilty of at least their sixth offence avoided prison.
Some 36,028 were not jailed despite 15 or more previous offences and just under 16,232 avoided prison despite 25 or more previous offences. The data was obtained under the Freedom of Information Act.
Peter Cuthbertson, author of the report and director of the Centre for Crime Prevention, said: "The courts are utterly failing to show they take crime seriously.
"Prison is the only sure way to protect the public from hardened criminals. The most prolific offenders are responsible for a growing percentage of all crime, and locking them up would have a massive impact on the crime rate.
"New Zealand recently fought rising crime by letting criminals know that it is 'three strikes and you're out'. In Britain, we don't even have 300 strikes and you're out."
Some 2,098 offenders found guilty of a crime in 2012 were not jailed despite 50 or more previous offences, the figures showed, while 409 avoided prison after 75 or more previous offences.
Elsewhere, the data shows 121 avoided prison after 100 or more previous offences, 36 were not jailed after 150 or more previous offences, eight avoided prison after 200 or more previous offences, four were not jailed after 250 or more previous offences and one avoided prison after 300 or more previous offences.
Both Dyfed-Powys Police and West Mercia Police refused to comment on the findings, saying sentences were matters for the courts.
But Justice Secretary Chris Grayling defended the Government's record on sentencing. He said: "If we want to stop there being more victims of crime we've got to do something about the reoffending rates in this country, which have been static for a decade. If we don't change the way we deal with offenders, those rates aren't going to change either.
"I want people to have faith in our criminal justice system, and I want them to know that people are punished quickly, effectively and properly."
Star comment: Are courts going soft on crime?