It is much more common in women who are pregnant for the first time, and its frequency drops significantly in second pregnancies.
The frequency of lynching dropped in the 1930s.
In winter, frequency dropped to between one and two round-trips per day.
As people traveled east the frequency of many alleles dropped or disappeared from migrants.
The frequency of that bending mode will likewise drop.
The frequency on this line drops to hourly in the evenings.
Guernsey is having its frequency dropped to one Saturday flight.
The frequency of attacks dropped dramatically, but his new home wasn't the kind of place where friends could just drop in.
On weekends, the frequency drops to four flights a day each way.
The frequency of yellow cards dropped significantly in the semifinals, when players grew more cautious.