GRB's occur once per day. over 10 billion years thats 3650 billion bursts (in the observable universe?). I think there are said to be around 100 billion galaxies in the observable universe so does that mean that 36 bursts occur in each galaxy? http://www.faqs.org/faqs/astronomy/faq/part8/section-4.html I wonder how large a galaxy has to be before it has a supermassive black hole? I wonder how many globular clusters there are and how that compares to the number 3650 billion?