You left out greater than 100% for those who take work home.
I used to work in a call center where I was working essentially 100% of the day most of the time. I hated it. Now I work as a web developer, so I work in bursts of creativity usually. Most days I’ll be 50% work and 50% not work, which includes time where I am FTP-ing files around, waiting for clients to show up to meetings, and wasting the last 20 minutes of the day because there’s no way I’m starting a project then. I’d say I strictly “Goof off” maybe 30% of my time, with permission from my boss who understands sometime you need to have a break and think stuff through in order to do brilliant work. Then again, some days it’s go go go and I work from the moment I get in until the moment I leave, no lunch, and work at home too.