keep in mind that data can only tell you so much...you need to ask the clinic about the cases they take - Boston IVF tends to take tough cases that have low chance of success, but they try anyway. Some clinics choose to only take cases they feel have a strong chance of success.
At the end of the day, the number one factor you need to have is trust and confidence in your doctor. So regardless of any data, or anyone else's experience, you need to go with your gut - who do you trust?