You can compare metrics between time periods with the Table chart. The comparison feature is available when you select week, month, or quarter as the row for the chart:

Once you've created the chart, you can control the display of the trend in the chart settings:

When checked, the chart displays the change percentage for the selected column:

The percentage is calculated by comparing each week/month/quarter with the previous one. The percentage shows the change (increase or decrease) between the values.