When a candidate gets more votes than required to get elected, the excess votes transfer to the voters next preferences. However, to ensure that every vote for said candidate is treated equally, what transfers is a fraction of each vote, so we don't get a situation where some votes transfer (ie. count twice), and some votes don't (also would be impossible to fairly determine which votes would transfer, and which would not). So if say Jenny Kwan gets 10% more votes on the first ballot than the number required to win, 10% of every first place vote for Jenny Kwan transfers to the voters next preference (rather than having 10% of votes transfer in their entirety, and 90% not transfer at all).