When you choose to view your progress under time ranges, your average completion rate, total completed and skipped will be calculated with habits whose goal period falls within the time range:
Except the Year time range, each column (in bar chart) or point (in line chart) will represent your data in a day or a group of days, so it will calculate the data of daily habits only.
When you view the Year time range, each column or point will represent data in a month, therefore, it can include all habit types (daily habits, weekly habits, monthly habits).