In 2007, there were 112,637 people residing in Trento, of whom 48% were male and 52% were female. Minors (children ages 18 and younger) totalled 18.01 percent of the population compared to pensioners who number 19.37 percent. This compares with the Italian average of 18.06 percent (minors) and 19.94 percent (pensioners). The average age of Trento residents is 41 compared to the Italian average of 42. In the five years between 2002 and 2007, the population of Trento grew by 5.72 percent, while Italy as a whole grew by 3.56 percent. The current birth rate of Trento is 9.61 births per 1,000 inhabitants compared to the Italian average of 9.45 births.
Question: How many years did it take for Italy's population to grow by 3.56 percent?
Answer: five years