[Bro] number of connections to the same port in 100 connections

[Salman, Tara]

Hi everyone, 
I am trying to find the number of connections having the same source ip and destination port in the last 100 connection using bro commands 
I managed to get the number in all connections using: 
bro-cut id.orig_h id.orgi_p < conn.log | sort| uniq -c| sort -rn  

which is working fine but i need to modify this to include only the last 100 connections in the log file. is there a way to do that ? 

thanks in advance