It's enough to look at demographics:
Serbia:
1991: Serbs - 6,616,917; Bosniaks - 176,401; Albanians - 74,303; Croats - 97,344;
2011: Serbs - 5,988,150; Bosniaks - 169,905; Albanians - 61,647 (2002, boycotted 2011 census); Croats - 57,900;
Croatia:
1991: Croats - 3,736,356; Serbs - 581,663...