I wouldn't call a 4,000 average difference pretty small but that's just me. In any case, again from what I've seen bottom and midtable teams in Spain do enjoy better attendance percentages in their stadiums.
18/20 for Spain. (the numbers are from this season)
After the top 6 the differences aren't too big, though.
Barcelona 79,285----------Internazionale 52,571
Real Madrid 72,000----------AC Milan 46,023
Atlético Madrid 43,500----------Napoli 36,857
Valencia 39,199----------AS Roma 31,625
Sevilla FC 37,125----------Lazio 28,375
Athletic Bilbao 34,857----------Bari 24,375
Real Zaragoza 27,333----------Genoa 24,241
Real Sociedad 25,857----------Palermo 24,111
Espanyol 25,571----------Sampdoria 22,122
Málaga 22,142----------Fiorentina 22,113
Hercules 22,000----------Juventus 21,804
Sporting Gijon 20,428----------Bologna 19,125
Villarreal 18,357----------Cesena 15,961
Deportivo La Coruña 16,428----------Lecce 14,944
Osasuna 16,357----------Parma 14,800
Racing Santander 14,857----------Udinese 13,268
Levante 14,857----------Cagliari 13,125
Almeria 12,571----------Catania 12,746
Mallorca 12,142----------Chievo Verona 10,971
Getafe 9,625----------Brescia 10,750