25.000 is the total number of the tickets available for the 2004 Lene Marlin's tour in Norway.
Here are the number of tickets for each location:
3rd Dec: Stavanger, Tennishallen 2500 tickets
4th Dec; Oslo, Oslo Spektrum, 9000
7th Dec: Bergen, Haukelandshallen, 4000
9th Dec: Trondheim, Tent I Death-valley, 4000
11th Dec: Bod°, Bod° Spectrum, 2500
13th Dec: Troms°, Troms°hallen, 2500