Study the given table and answer the question that follows.

The table represents the expenditure of a company (in thousand rupees) per annum over the given year.

Year	Expenditure
	Salary	Transport	Interest	Tax
2018	200	90	3	80
2019	250	100	2.5	100
2020	300	120	3	70
2021	350	130	3.5	80

What is the average amount of salary per year, which the company has to pay during these four years?