How can I have more than 10 entries in the iftop text output?

I want to monitor the network traffic and save the results to a file under Debian Linux. I am using iftop to achieve this. Following command does the job: iftop -tnNBP -s 3600 -o destination > output.txt 2>&1 My problem is: if more than 10 connections are present during the monitoring time (1 hour), only the first 10 is saved to the output.txt file. The rest of the connections are not shown. How can I configure the iftop to display all of the connection (regardless how much they are/were).