Doug is a manager of a local supermarket. In an attempt to gain a better understanding of the sales of his produce he monitors the sales of blueberries across the year. In January, at a price of $3.50 per punnet, 200 blueberry punnets are sold daily. In July at the same price, 300 punnets are sold and then in September at the same price, 110 punnets are sold daily.

Which of the following statements are true:

From January to September there has been an increase in demand.

From July to September there has been no change in demand, only quantity demanded.

From January to July there has been an increase in demand. However, there is no indication as to why this occurred.

From July to September there has been a positive movement in demand.