re = /, \d{4}(?:-\d{2})?$/m
str = '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'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html