While motorcyclists continued to mount protests against the stiff rise in insurance premiums for next year, the National Insurance Institute (INS) revealed that accident claims by the government-owned company costs them eight billion colones per year in medical costs.

In 2011, INS shelled out 53% of its medical expenses to treat motorcyclists of injuries connected with their means of transport.

INS figures show that that medical costs were up 28% over the year before. Not only is the figure above that paid out for auto accidents (5.253 million colones) but the amount paid out for treating 4 wheeled vehicle accident victims has actually dropped a percentage point.

This is why the disparity between the hike in obligatory insurance rates for motorbikes (up 25%) while car drivers pay only 9% more. Guillermo Constenla, the insurance firm’s president, defends the hike as the only way to keep up with spiking costs.

But two-wheel enthusiasts insist on protesting the premium hikes — in fact another one is scheduled for Tuesday, to ride from the INS headquarters in eastern San Jose to the Presidential offices in Zapote.

Eugenio Badilla, head of the National Civic Committee of Motorcyclists says his group wants to see a national committee convoked with government officials on it to probe the issue.

But Constenla holds firm, saying that costs rule the premium rates. It would be unlikely, barring some sort of government subsidy of motorcycle insurance, that the actuarial tables would be overturned.

The amount INS will get from the projected 2013 premiums is 37.9% of the total, more than 10 billion colones. Under the circumstances, that’s about as low as it can go.