Hi there! Let me start by saying I'm not an English native speaker but as far as I know both the first and second sentences are correct. I'm going to post some examples that I personally think are correct: I have one year of experience = I have one year’s experience She has twelve years of experience = She has twelve years’ experience

Both 1 and 2 are correct, however 1 sounds the cleanest : )

And I second what Briony said. The first and second sentences are fine, and it is also a joy to see a correct apostrophe being used after 'years'. Your punctuation is superior to that of the majority of native English speakers.

As others have said, 1 and 2 are both fine. I just want to thank you for putting the apostrophe in your second sentence. Here in the UK many, many native speakers don't know to do this!

# 2 should be used on a resume