This important and useful chart was on the National Snow and Ice Data Center site on August 8, 2017:
But I found it unusually hard to read. Here is my spruced-up version:
No more hard-to-read vertical text. Zero-based, thus enabling one immediately to see how much lower the extent was in 2012 and is projected to be in 2017. Date of measurement prominent in the title area. Labels close to their items, so the eye doesn’t have to travel back and forth to interpret. Percentage of total ocean area on the left axis, as opposed to square km values in the original, for which one would have to know that the Arctic Ocean’s total area is 14m+ square km in order to realize that the ice extent remains nearly 100% at the start of May.
To me, the original’s main errors were 1) not being zero-based, which forces you to imagine the full picture in order to grasp the real meaning, and 2) expressing measured ice area on the left axis instead of % of total Arctic Ocean area, forcing you to look elsewhere to find out how full or empty the Arctic Ocean actually was/is of sea ice. A basic rule of user interface design is, “Don’t Make Me Think!” unnecessarily. That’s the title of my favorite user-interface book, written lightly and gracefully by Steve Krug and well worth a read.