[
.B \-a
] [
+.B \-d
+] [
.B \-v
] [
.B \-r
Without this option, the second and subsequent reports show statistics
for the time since the last report.
.TP
+.B \-d
+Show data rate (kB/s) instead of bytes.
+.TP
.B \-c \fIcount
Repeat the display
.I count