Simplify the following text for a Grade 5 native English-speaking person.
Original: A compromise was reached and on August 27 , 1998 , the 1998 Concorde Agreement was signed which accommodated the three teams and which expired on December 31 , 2007 .
Simplified: On 27 August 1998 , the 1998 Concorde Agreement was signed . This agreement expired on 31 December 2007 .