Trend Analysis of Organic Produce Purchases

A market research firm analyzed the purchasing trends of customers at a grocery store over the last year. They found the following:

- In January, 150 out of 300 surveyed customers reported buying organic produce.

- In July, this number increased to 200 out of 350 surveyed customers.

- In December, 180 out of 400 surveyed customers reported buying organic produce.

Using this data, determine the overall trend in the purchase of organic produce over the year.