<prompt> Translate the following text to SwahiliFederal Reserve researchers estimated that, as of the early 1990s, U.S. investment including education and R and D had declined as a share of GDP since the 1970s.  <response>: Watafiti wa Fedha ya Marekani walikadiria kuwa, kuanzia mwanzoni mwa miaka ya 1990, uwekezaji wa Marekani, ikiwa ni pamoja na elimu na RD, ulikuwa umepungua kama sehemu ya Pato la Taifa tangu miaka ya 1970. 