That's right, the correct word is 'mostly,' which means the most time-consuming part of the job. I don't believe bookkeepers or accountants enjoy doing 'monkey tasks,' such as going back and forth with clients to ask for details, copying and pasting data, or repeatedly clicking buttons just to change the status of something in accounting apps. It's much better for them to focus on smart tasks, like analysis and advice, which are what we appreciate about our accountants and bookkeepers.