4 times in 10 years?

Ignoring snigger snogwriter stuff, I'd guess the following as pretty common nowadays: -
The Gay Fusilier
The Bold Fisherman
Bring us a Barrel
The Little Pot Stove
The Nutting Girl
The Grey Cock
New York Girls
Tell me Ma (Yecch!)
The Black Velvet Band (Yecch!)
The Lincolnshire Poacher (Yecch!)
The Drunken Sailor (Yecch!)
The Mingulay Boat Song (Yecch!)
Haul Away for Rosie
Haul Away Joe
Blood Red Roses
The Alabama
Shenandoah
The Mary Ellen Carter
Barrett's Privateers
The Trees they do Grow High
Waiting For the Day
Lowlands
The Rosie-ana
South Australia (Yecch!)
The Miner's Lifeguard
Blackleg Miner (usually murdered)
Tolpuddle Man