CentOS 6.7のDefault設定なんだけど、num=3の意味って何？

# iptables -L --line-number
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
2 ACCEPT icmp -- anywhere anywhere
3 ACCEPT all -- anywhere anywhere
4 ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh
5 REJECT all -- anywhere anywhere reject-with icmp-host-prohibited