how many clubs are represented?
12
col : season | competition | round | club | home | away row 1 : 1985–86 | uefa cup winners' cup | 1r | hjk helsinki | 1–2 | 2–3 row 2 : 1986–87 | uefa cup | 1r | fc barcelona | 1–1 | 0–0 row 3 : 1987–88 | uefa cup | 1r | fk partizan beograd | 2–0 | 1–2 row 4 : 1987–88 | uefa cup | 2r | wismut aue | 2–0 | 0–1 row 5 : 1987–88 | uefa cup | 1/16 | fc barcelona | 1–0 | 1–4 row 6 : 1988–89 | uefa cup winners' cup | 1r | lech poznań | 2–3 | 0–1 row 7 : 1990–91 | uefa cup winners' cup | 1r | olympiacos piraeus | 0–2 | 1–3 row 8 : 1991–92 | uefa european cup | 1r | ifk göteborg | 1–1 | 0–0 row 9 : 1996–97 | uefa cup winners' cup | qr | humenné | 0–2 | 0–1 row 10 : 2009–10 | uefa europa league | 2qr | motherwell | 1–0 | 1–8 row 11 : 2011–12 | uefa europa league | 1qr | fk budućnost | 1–2 | 3–1 row 12 :  |  | 2qr | fk jablonec 97 | 0–2 | 1–5 row 13 : 2012–13 | uefa europa league | 1qr | budapest honvéd | 0–1 | 0–2
how many clubs are represented?
Season Competition Round Club Home Away
1985–86 UEFA Cup Winners' Cup 1R HJK Helsinki 1–2 2–3
1986–87 UEFA Cup 1R FC Barcelona 1–1 0–0
1987–88 UEFA Cup 1R FK Partizan Beograd 2–0 1–2
1987–88 UEFA Cup 2R Wismut Aue 2–0 0–1
1987–88 UEFA Cup 1/16 FC Barcelona 1–0 1–4
1988–89 UEFA Cup Winners' Cup 1R Lech Poznań 2–3 0–1
1990–91 UEFA Cup Winners' Cup 1R Olympiacos Piraeus 0–2 1–3
1991–92 UEFA European Cup 1R IFK Göteborg 1–1 0–0
1996–97 UEFA Cup Winners' Cup QR Humenné 0–2 0–1
2009–10 UEFA Europa League 2QR Motherwell 1–0 1–8
2011–12 UEFA Europa League 1QR FK Budućnost 1–2 3–1
2QR FK Jablonec 97 0–2 1–5
2012–13 UEFA Europa League 1QR Budapest Honvéd 0–1 0–2
12