How many sunflowers to i need to make a litre of sunflower oil?

Just curious but does anyone know how many exactly are needed to make up 1 litre?How many sunflowers to i need to make a litre of sunflower oil?
According to appropedia.org:





';Oil yield is 1.25 l from approximately 10 kg of undecorticated seed, which is equivalent to an extraction efficiency of 38% for a low oil-content seed (30% total oil) or 23% for a high oil-content seed (50% total oil).





Laboratory studies have shown that the yield of available oil can be increased to about 53% by using sunflower kernels, and that the hot water for one extraction can be recovered and used for further processing, thus saving on energy and water consumption.';





Go to this website to see the process:


http://www.appropedia.org/Small_Scale_Ve鈥?/a>