This is the average growth in the Dividends Per Share (DPS) for the last 3 years. Dividend per share (DPS) is the total dividends paid out over an entire year (including interim dividends but not including special dividends) divided by the number of outstanding ordinary shares issued.
The CAGR formula is the following: (current year's DPS / DPS 3 years ago) ^ (1/3) - 1
If the starting year's DPS is zero, the CAGR is not defined.
A growing dividend per share can be a good indicator of the financial health of a company. It suggests that the company's management believes that growth can be sustained.