Yes, we know that most offenders who receive this kind of sentence usually come into the system at around the age of 20 or 21. About 40% come in between the ages of 20 and 39 and they go out at their first release around the age of 44, 45, 46. So they're serving anywhere from 21 to 23, 24 years of a sentence for indeterminate sentences.
Evidence of meeting #46 for Justice and Human Rights in the 40th Parliament, 2nd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was murder.
A recording is available from Parliament.