You can
put this solution on YOUR website!a) in 2003 (55 is the most)
b) Look at all difference between two years (that follow each other)
1998-1999 -> 5
1999-2000 -> 15
2000-2001 -> -10
2001-2002 -> 5
2002-2003 -> 10
Answer: between 1999 and 2000
Greets,
Scriptor