Average Visitors to Science Projects

During a science fair, students presented their projects and recorded the number of visitors for each project. The data is shown in the following line graph:

Number of Visitors to Science Projects:

Day 1: 20 visitors, Day 2: 35 visitors, Day 3: 30 visitors, Day 4: 50 visitors, Day 5: 45 visitors.

What was the average number of visitors over the five days?