<prompt> Translate the following text to EnglishKatika miaka ya 1990, kiasi cha sekta ya NHH-HH kiliongezeka, lakini kiwango chake cha ukuaji wa kila mwaka kimekuwa kikipungua.  <response>: In the 90s, the volume of NHH-to-HH sector has increased, but its annual growth rate has been falling. 