In the 2010 general election the Sweden Democrats for the first time crossed the four per cent threshold necessary for parliamentary representation.
Evapotranspiration (ET) is the sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. Evaporation accounts for the movement of water to the air from sources such as the soil, canopy interception, and waterbodies.
Evapotranspiration is calculated by two methods, first PAN evaporation method and other way to calculate ET is by empirical methods using the climatic data. Allen et. Al., (1998) (FAO-56) ET calculation formula is widely used. You are discussing river discharges and rainfall data, that can not estimate ET.