An annual report released Monday shows that charitable giving in the United States grew nearly 4 percent last year after two years of steep declines, which some experts say is a sign the economy is slowly rebounding. Individuals and corporations donated an estimated $290 billion last year, an increase of $10 billion from the previous year, according to the Giving USA Foundation, which has tracked charitable giving in the country since 1956. Donations to education, health institutions, and arts and humanities organizations were up, while overall corporate donations rose nearly 11 percent, the study found.