As I noted in this post, I recently digitized my writing calendars. I used to print them out and save them, so I'd know how much I wrote the previous year. These hard copies were the only means I had to preserve the record of what I'd done.
That's changed with cloud data services. I was able to go into my calendar app on my MacBook Air and enter in data for previous years. I chose to enter in everything since 2003. That was the first year in a few that I had enough of an event schedule to see how it, as well as other things, impacted how much I wrote month by month. That said, my goal of writing 4 pages per writing session goes back to 2001. I didn't have any new books out between 1999 and 2003, so I chose not to bother entering in the stats for 2001 and 2002.
(As an aside, I'm not entirely trusting everything to the cloud. What I also do is use my printer app to create a PDF file of each year, so I have files on my hard drive in addition to the cloud data.)
I was a bit bummed, coming to the end of 2015, that I hadn't written as much as I could have. Digitizing the calendars reminded men that I'd had worse years that 2015. It also reminded me that I didn't always write as much as I could have because I was researching nonfiction books. Another reminder was that, due to the nature of writing such books (like transcribing quotes, or cutting and pasting newspaper stories so that I only had research material, and not lots of excess paper), there were days when I only wrote a single page.
Something else that I had to notice was how recently I adopted the current schedule. For those who forgot (or are new), my schedule is: two sessions a day, Monday-Friday, and one session Saturday. The goal for each session is to write 4 pages. I remembered that, for a long time, my goal was 4 pages a day, not a session. There was a great deal of writing I could have done had I adopted the present schedule sooner.
So the exercise was helpful, in that it allowed me to see that I am creating more than I used to.
There's one other aspect to this effort that I want to pass along. It's the power of a schedule. If you make the effort to work at your day, day after day, you will see progress. Projects will get started, be worked on, and completed. Old ideas will turn into works. New ideas will pop into your head. Those new ideas will become works, and the process starts over again.
Sometimes it's terribly helpful to look back at where you were.