IV curve on this solar panel datasheet
The unit is mA/cm2. You need to calculate the area of each cell. 2cm * 0.471cm = 0.942cm2. The panel you are looking at has 12 cells connected in series.

The voltage at max power on the graph is roughly 0.56V. 12*0.56V = 6.72V ~ 6.7V

The current at max power is roughly 39mA/cm2.   39m/cm2 * 0.942cm2 = 36.73mA ~36.6mA