In this case, a drop off needs to be compared to a peak value which 1984 is not. 1984 is before the 1986 peak. I'm not saying they're exactly identical but it's

In this case, a drop off needs to be compared to a peak value which 1984 is not. 1984 is before the 1986 peak. I'm not saying they're exactly identical but it's clear that there are similar patterns. Perhaps not "nearly" identical, but similar enough.