Shares of Boston-based Carbonite Inc., a provider of cloud backup services, jumped Tuesday after it disclosed financial results for the fourth quarter and the year. Revenue for the period was $23.7 million, an increase of 37 percent from $17.3 million in 2011’s fourth quarter. The company’s net loss narrowed to $2.2 million, compared to $6.1 million in 2011. For the year, revenue jumped to $84 million, an increase of 39 percent from $60.5 million in 2011.