Even medium-to-high risk offenders become less likely to offend than the baseline over time. Most people convicted of sex offenses do not reoffend sexually. In other words, the great majority of sex crimes are committed by new offenders, not repeat offenders. A study by the Prison Policy Initiative found that almost 50 percent of Grand Rapids is off-limits to registrants and much of the other 50 percent contains non-residential areas. By far the greatest danger of sexual abuse of children is not from strangers, but rather from relatives, sitters, friends, etc. Changing Exclusion Zones Depending on How You Measure foot geographic zones drawn around each of three nested protected areas: See the map below. The risk that someone will commit a new sex offense varies significantly among offenders. School exclusions zones apply to all registrants, even to those whose crime had nothing to do with children and who have never been found to be a danger to children. Because registrants and law enforcement officials have no way of knowing where property lines are, they cannot know where exclusion zones begin and end. In fact, studies have revealed that proximity to schools and other places where children congregate had little relation to where offenders met child victims. All people with records, including individuals convicted of sex offenses, are less likely to recidivate when they have strong family and community support, stable housing, educational opportunities, and good jobs. Individuals who reoffend usually do so within three-to-five years. The risk of a new first sex offense is about 3 percent in the general male population. As the image below shows, the size and shape of exclusion zones depends on how you measure them. This is why the federal district court held the exclusion zones to be unconstitutionally vague. It is also impossible to know where exclusion zones are because the size and shape of the zone depends on whether you measure from the school door, the school building, or the school property line.