some opponents have questioned the proponents' life expectancy argument, making the comparison between the growth of copyright terms and the term of patents in relation to the growth of life expectancies. life expectancies have risen from about 35 years in 1800 to 77.6 years in 2002. while copyright terms have increased threefold, from only 28 years total (under the copyright act of 1790), life expectancies have roughly doubled. moreover, life expectancy statistics are skewed due to historically high infant mortality rates. correcting for infant mortality, life expectancy has only increased by fifteen years between 1850 and 2000.