Think of this. If a woman was in her 20's when she had her first IR experience.
If it was during the 1950's, she would be between 90 and 81 years of age.
If it was during the 1960's, she would be between 80 and 71 years of age.
If it was during the 1970's, she would be between 70 and 61 years of age.
If it was during the 1980's, she would be between 60 and 51 years of age.
If it was during the 1990's, she would be between 50 and 41 years of age.
If it was during the 1950's, she would be between 90 and 81 years of age.
If it was during the 1960's, she would be between 80 and 71 years of age.
If it was during the 1970's, she would be between 70 and 61 years of age.
If it was during the 1980's, she would be between 60 and 51 years of age.
If it was during the 1990's, she would be between 50 and 41 years of age.