good luck with that one. 13 years old "The federal age of consent in Japan is 13 years old under the Japanese Criminal Law Code. However, all municipalities and prefectures have their own particular laws such as Tokyo's Youth Protection Law which prohibit sexual activity with youths who are under 18 years old in most circumstances."
In the USA, there are 19 states that have NO minimum age for marriage, as long as the parents consent. Since the year 2000, there are children as young as 12 getting married, usually to a much older spouse.
You tell me what criteria they used, because apparently you know it. To all people the same questions were asked, so not the law in a specific area was the basis. In a survey a number of questions are asked to a lot of people. They all receive THE SAME questions. If not it is not a survey.
I am not the one stating as fact that the same criteria were used. Thanks for acknowledging you do not know.
In a survey all parties receive the same questions, if not it is not a survey. As you cannot proof that this survey was manipulated the survey is what it's definiton tells it is. Thanks for acknowledging that you do not know that. You are stating that they did not receive the same questions.