My papa tell me say for their time, before you reach 25, you done already marry or about to. But today, 30 self never put marriage as priority. Plenty good reasons dey sha o but some their reasons no reason enough to be single at certain age.
Maybe in Southern part. Go to North and see the difference. It has been estimated that by 2050, Nigeria population would surpass 1 billion if they continue to reproduce the way they are reproducing and nothing changed till now. More population are coming from the Northern part and they marry fast. Especially their females.