Table:
text: 1998–99 Chelsea F.C. season
UEFA Cup Winners' Cup
UEFA Cup Winners' Cup
Date_ Round Opponent Venue Result_ Attendance
17 September 1998 R1 Helsingborg H 1-0 17714
1 October 1998 R1 Helsingborg A 0-0 12348
22 October 1998 R2 Copenhagen H 1-1 21207
5 November 1998 R2 Copenhagen A 1-0 24188
4 March 1999 QF Vålerenga H 3-0 34177
18 March 1999 QF Vålerenga A 3-2 17936
8 April 1999 SF Mallorca H 1-1 35524
22 April 1999 SF Mallorca A 0-1 18848

Question: What is the average attendance for Chelsea FC in the 1998-99 UEFA Cup Winners' Cup season if the date is 1 October 1998?

Question: What is Chelsea FC's opponent of the 1998-99 season if the date is 17 September 1998 in the UEFA Cup Winners' Cup?

Question: When is Chelsea FC UEFA Cup Winners Cup 1998/99 season, when is opponents, when is 8 April 1999?