I don't think I've seen any reliable estimates of that figure. There has been some accounting, for instance, of refugees who have been killed outside the country, once they have made it across the border, for instance. I talked about the fact that 85 refugees trying to reach Israel, most of whom were Eritrean, have been killed in the Sinai over the last five years. But because of this impossibility of getting access to meaningful information inside the country, the numbers of individuals who are shot and killed by Eritrean forces as they're nearing the border or trying to cross into neighbouring countries is simply unknown. We know it's a very serious concern now.
On February 9th, 2012. See this statement in context.