WASHINGTON (Reuters) - The U.S. health bill will account for 19.8 percent of the nation's spending by 2020, up from 17.6 percent in 2009, outpacing projected average annual GDP growth, researchers said on Thursday. (http://feeds.feedburner.com/~ff/reuters/topNews?d=yIl2AUoC8zA) (http://feeds.feedburner.com/~ff/reuters/topNews?i=fDD5bzG5tJI:7YxAVNNdZeQ:V_sGLiPBpWU) (http://feeds.feedburner.com/~ff/reuters/topNews?i=fDD5bzG5tJI:7YxAVNNdZeQ:-BTjWOF_DHI) (http://feeds.feedburner.com/~r/reuters/topNews/~4/fDD5bzG5tJI)