The “rise of the variant” is clearly seen in the percent of CGC submissions which have any type of variant notification on the CGC label, separated by the date of the book. The 1966 variant “spike” is related to Golden Record Reprints from Marvel, and the 1976-1977 “spike” is for 30-cent and 35-cent variants. 1990’s spike is primarily related to Spider-man #1 (1990).
The percentage of CGC submissions which are also part of the Signature Series program is shown in the chart above. These are overall percentages for all comic years. Specifically focusing on comic books printed 2010 to 2016, the annual percentage of books CGC graded each year from 2013 to 2016 was about 36% in the Signature Series program.
As of January 17, 2017, a total of 3,233,122 comic books appear on the CGC Census.
The following chart shows the total number of submissions (universal, signature, restored, and qualified) according to the CGC census data compiled at CGCdata.com, with the oldest decades at the bottom and newest at the top. The numbers for 1930s comics are included, but are so low that they do not appear in the chart.
The portion of each CGC grading year(s) attributed to each decade of comic books is shown as a percentage in the chart below.