The portion of unused Bitcoin is huge. According to a study conducted by the California University, 64% is the estimated part of present Bitcoins on the blockchain are still unused. There are Bitcoin wallets which are not used for a long time and also wallets where users who have lost their private keys and who are not still able to use their bitcoins.
There a lot of address’ like these two:
1FeexV6bAHb8ybZjqQMjJrcCrHGW9sb6uF – still has 75,957 Bitcoins
12tkqA9xSoowkzoERHMWNKsTey55YEBqkv – still has 28,150 Bitcoins