Web scraping

Often data on web pages is not in the format you want. Web scraping is the process of extracting and organize such data.
This assignment uses data from a reasonably well-formatted website.
(More complex data can be approached with scrapy or `beautifulsoup')
Python code [85 points]
Starting from the scaffold python code implement the four functions

• [20] load_data(): Load data from pickle
• [25] get_date_changes(): Return a list of [index, year] changes.
  Make sure to include the end points.
  Index will the first occurance that the year is different
  and year will be the last two as a string (`22').
• [20] plot_data(): Plot each column with the labels
• [20] plot_finalize(): Set up graph ticks, axis ranges, grid, and legend.

Carefully read the comments and follow the style. This will create a plot of rates vs time with twelve graphs.
Observation [3 x 5 points]

• What events are associated with the largest three downward changes in the graphs?

Submit (via canvas, see canvas for due dates)

• Python code file (.py)
• Document containing observations (text) and the plot