By MIKE SCHNEIDER (Associated Press) The rate of businesses in the U.S. using AI is still relatively small but growing rapidly, with firms in information technology, and in locations like Colorado and the District of Columbia, leading the way, according to a new paper from U.S. Census Bureau researchers. Overall use of AI tools by firms in the production of goods and services rose from 3.7% last fall to 5.4% in February, and it is expected to rise in the U.S.