# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/, \d{4}(?:-\d{2})?$//gm;t' <<< "Percent of adults with a high school diploma only, 2000
Percent of adults completing some college or associate's degree, 2000
Percent of adults with a bachelor's degree or higher, 2000
Percent of adults with less than a high school diploma, 2014-18
Percent of adults with a high school diploma only, 2014-18
Percent of adults completing some college or associate's degree, 2014-18"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html