IE has been the most popular web browser since 1999, with up to 95% usage share during 2002/2003 with IE5 and IE6. Since its peak of popularity, its usage share has decreased to 55% due to rival web browsers, and is slowly trending downward. Microsoft spent over $100 million per year on IE in the late 1990s, with over 1000 people working on it by 1999.