Consider following statements regarding Goods and Services Tax (GST):
1. GST is an indirect tax levied on manufacture, sale and consumption of goods as well as services at the national level.
2. Only central government can levy GST while state government will collect its proceeds on GoI's behalf.
3. Exports would not be subject to GST, thus helping India to expand its manufacturing sector.
4. Central government will compensate states for potential lost revenue.
Which of the above statements are correct?