The Gross Yield is all of the distribution payments for the past year divided by the current unit price. This is shown as a percentage. It shows the income stream you can expect based on an investment made today as separate from any capital growth (increase in share price) that might occur.
It is not guaranteed, although listed companies are reluctant to reduce or halt their dividends. See What’s the difference between a dividend and a distribution? for more.
You can see more about the expected gross yield of our funds here.