such as increased affluence, the need for longer education, and greater mobility have lessened the appeal for arranged marriages, and these trends have affected criteria about which possible partners are acceptable, making it more likely that pairings will cross previously impenetrable. 96 Detectives investigate former amorous relationships and can include fellow college students, former police officers skilled in investigations, and medical workers "with access to health records." 96 Transsexuals and eunuchs have begun using Internet dating in some states in India. Most Chinese university women can agree on one thing: Dating is difficult. 22 There is substantial data about online dating habits; for example, researchers believe that "the likelihood of a reply to a message sent by one online dater to another drops roughly.7 percent with every day that goes by". 145 Teenagers and college-aged students tend to avoid the more formal activity of dating, and prefer casual no-strings-attached experiments sometimes described as hookups. Men are more likely than women to flirtext but for those who consider themselves in a relationship, women are more likely to engage in the activity.