Not necessarily. Where rape is concerned, statistics are a little squirrely. One would have to assume all incidents of rape are reported, and we know they are not.
It could be argued that fewer instances are being reported because the definition of what is rape is less clear to young women. (By that I mean, 'date rape' may be occurring much more frequently, but it's not reported because the victim's don't think it fits the criteria for a rape.)
Surveys of women across the decades, indicate that the rate of reportage has increased during that time. In other words, the rate has gone down, even as it is more likely that each incident of rape will be reported.
It could be argued that fewer instances are being reported because the definition of what is rape is less clear to young women. (By that I mean, 'date rape' may be occurring much more frequently, but it's not reported because the victim's don't think it fits the criteria for a rape.)
Actually, "date rape" reports have skyrocketed. Unfortunately, what is now considered "date rape" is what used to be called "buyer's remorse."
The reporting rate for rape has greatly increased over the past few decades for two reasons -- one good and one bad. The good one is that the stigma attached to victims has been greatly reduced (e.g. the suggestion that "she was asking for it" has become much less acceptable in both polite society and defense arguments). The bad one is that dubious cases in which a change of heart after the fact is reported as "date rape" have polluted the statistics.
Of course, an increase in the rape report rate makes the decline in total reports all the more striking, and all the more damning to the "porn turns men into rapists" theory.