It discussed the reoffending statistics of sex offenders and the prospect that every five years they stay crime-free in society, their probability of reoffending could decrease by half. Hanson claims that this is a result of physical ageing, including factors like declining testosterone levels, professional achievement, a loving intimate partner, decent friends, and few others. As a result, if the risk is 20% when someone leaves prison and they survive for 5 years, it is 10% risk; if they survive for 10 years, it is 5% risk. (Re-assuring risk 2007: Karl Hanson).