Tracking Solar Activity To edit this document: Create your own copy of the document by: Selecting "File" "Make a copy" to create a new copy in Google Docs, or Selecting "File" "Download" to save the document in the file format of your choice. The activity of the sun can be measured by counting the number of sunspots that are visible on the photosphere. Astronomers track how solar activity changes from year to year in an effort to learn more about the sun. Below is a table containing the number of sunspots recorded for 25 years from 1996 to 2021. Year Sunspots Year Sunspots 1996 12 2009 5 1997 29 2010 25 1998 89 2011 81 1999 137 2012 85 2000 174 2013 94 2001 171 2014 114 2002 164 2015 70 2003 100 2016 40 2004 66 2017 22 2005 46 2018 7 2006 25 2019 4 2007 13 2020 9 2008 5 2021 30