If we assume Nigerians 100% depend on revenue from oil export then we must be magicians to have survived this long.
The maths below explains it:

Average price per barrel of oil = $100
Estimated cost of producing one Barrel (bbls) = $30
Profit from one barrel of oil = 100 – 30 = $70
Daily production rate = 2,000,000bbls
Nigeria population = 170,000,000
1dollar = N197

Assumptions:
1. 100% of profit from sale of oil goes to the Nigerian government. But this is not true as it is often shared with multinationals and operators.
2. 100% of funds are owned by the government. But this is not true as loans are often used to fund a huge portion these transactions.
3. There are no loses. But this is not true as sometimes spills, damages often add to production cost.
Total revenue from sale of oil = 70 * 2,000,000 = $140,000,000
Revenue for one Nigerian per day = 140,000,000/170,000,000 = $0.8235
Revenue for one Nigerian per day = 197 * 0.8235 = N162
If all assumptions are eradicated, the money is a lot less.

Question(s):
1. Do we all live on an average of N162 daily?

Facts:
1. There is a lot more to the Nigerian economy than just oil which is being affected that puts so much weight on our currency.
2. With the level of looting of the oil revenue; something else is driving the economy which cushions this effect.
3. Nigeria can very well survive without oil.

on point.