English to Spanish Other Insurance HURRICANES

El texto habla de los P&I clubs no entiendo a que se refiere la palabra call, puede ser cuota?- El texto dice así "If at the end of the year, the claims exceeded their initial premiums, then an additional call was charged so that the clubs were non profit or loss making in respect of each year."
Aquí aparece otra vez "So alongside the mutual club structure, a professional specialist fixed premium market was established whereby there would be no additional calls, and where much lower limits of liability were offered "

Mil gracias como siempre