those countries have very high taxes. Ã°â¢The average annual growth rate for the European population from 1985 to 1995 was only. 0.28 percent; in the same period the population of Asia grew by 1.69 percent per year, and. that of North America by 1.33 percent annually.
The life span of sperm after ejaculation depends on the circumstances. Ejaculated sperm remain viable for several days within a woman's reproductive tract or in nutritive liquid (culture medium) in a lab setting. Fertilization is possible as long as the sperm remain alive â at least five days. Sperm also can be preserved for years when semen is frozen. With. Landon Trost, M.D. 1  Secondary infertility. 2  Paternal age.
The volume of a single ejaculate has declined from 3.40 ml to 2.75 ml. This means that men on average are now ejaculating less than half the number of sperm as men did 50 yrs ago. A drop from more than 380 million sperm to about 180 million sperm per ejaculate.Furthermore, the number of motile sperm has also dipped.he volume and content of the ejaculate depend on the length of time between ejaculations. The average volume of semen is 2.75 mililiters(ml) , ranging from 2-6 ml, the higher volumes following periods of abstinence.