Infertility is a year of actively trying to conceive without any type of protection. So we defined it as unprotected intercourse. What's really interesting is that what we define medically has a year of actively trying; it's actually very age-dependent as well. So for a woman who's less than the age of 35 and has been trying for a year or more, we would define that as in fertility. However, a woman who's over the age of 40, if it's more than three months, then we would find that. It's very age-dependent in changes and the large reason for that is with advancing age it becomes an egg issue or as women are heading towards the reproductive twilight they start running out of eggs and so we would define fertility a little bit more aggressively than if you were younger.