Macbook Air mid-2013 lasts about 6 hours

My MBA mid-2013 usually lasts about 6 hours now. It's been used for almost 4 years now. I use Chrome for internet browsing, mostly Facebook, Reddit and go over to other websites from these two websites. No other streaming or song playing or any other app runs that continuously syncs over the internet. I do use a number of extensions on Chrome - adblocker, lastpass, evernote, hover zoom+. My questions is, is 5-6 hours a normal battery life for 4-year old mid-2013 MBA with these settings or is is it time for me change the battery? The cycle count is at 380.