Most of these say that they were raped at follow-on parties after a night out.
The rape center at the Oslo Emergency Ward received 48 women since the beginning of July, compared to 20 at the same time last year. For the year as a whole, 165 women have contacted the center so far, compared to 130 at this time in 2005.
"Since the unreported numbers are so high in rape cases we will never know if this is because there have in fact been more rapes this year or if it is due to a higher share of the victims making contact," said medical director Henriette Myhre Waitz at the rape reception center.
Police have still made no progress in the attacks on six young women in Oslo this summer - two rapes and four attempted rapes - despite a large number of tips from the public.
Even those these attacks have attracted the most media attention, it is the post-party rapes that are overly represented in the center's figures.
"Rapes related to intoxication and late parties make up a much larger share than before. The good weather and long nights combined with intoxicants is perhaps part of the cause," said Endre Sandvik at the Oslo Emergency Ward.
Per Kristian Dotterud, manager of Reform - resource centre for men, urges men to take a more active role in discussing what they can do, and to consider the changing boundaries of sexual harassment.
"I believe men must take both an individual and collective responsibility. The problem with rapes must become a topic of male conversation. We do not have a direct responsibility for other men who rape, but this must become a topic for male discussion," Dotterud said.
