show percentage change over time

[simonmichael]

balance assets -M -% (eg) will show each account's percentage of the total on a given day. But there's no easy way to see the percentage change in an account's balance (or value) over time. register doesn't support -%/--percent. The roi command is the nearest thing.

[lestephane]

Indeed, this would be useful to quickly determine which monthly expenses are abnormaly higher than the previous month when doing a monthly eyeball check.