Since non-polar molecules are equally distributed and positively charged atoms in contrast with polar molecules. Thus, like fats oils and waxes, these materials are composed mainly of lipids or in the group of fats and are conspicuously insoluble with water. How do these substances interact with water? They are hydrophobic, thus, they don't "mix" with water. Unlike water and other polar molecules that are unequally and negatively distributed and charged making them able to bond with other molecules like oxygen and other polar molecules and substances.
Since the death rate is higher than the birth rate we can assume that it will be negative. 5-15 is -10 for their life. immigration is also lower than the emigration. 2-4 is -2. adding -2 and -10 will give us -12, hope this helps.