The hyphen is sometimes confused with dashes (figure dash ‒, en dash –, em dash —, horizontal bar ―), which are longer and have different uses, or with the minus sign −, which is also longer and more vertically centred in some typefaces.
According to this source the correct symbol to abbreviate year using two digits is an apostrophe:
When abbreviating a year, remove the first two numbers and indicate the omission by using an apostrophe:
- 2009 becomes ’09 (not ‘09)
- 2010 becomes ’10 (not ‘10)
- 2525 becomes ’25 (if we're still alive)
Notice I said apostrophe, not single opening quote.
You could use whatever you want on your resume, your choices will make your resume more or less effective, also depending on who will read and how you articulate different solutions for presentation.
