Two years ago, Dallas-area station The Hardline came up with its own definition of modern country: "You have to have a truck, girl, beer and/or liquor, farm equipment, mud/dust, rural setting like a river, jeans, boots, guns, critters. If you run out of things to talk about, just mention the troops."

This is a popular set of stereotypes, but one that needs tweaking.

We charted lyrics from 30 country songs, including this week's Top 10 (Jan. 24), the Top 10 from the final week of Florida Georgia Line's record breaking 22-week run at No. 1 (Aug. 24, 2013) and the Top 10 from a decade ago (Jan. 15, 2005).

Not a single song included a reference to firearms, and only one referred to farm equipment (Tim McGraw's 2005 hit "Back When"). There were very few mentions of critters (four), jeans (two) and boots (two), while a rural setting (12) and "mud/dust" (six) were slightly more common.

See if you can spot any differences between the remaining three categories below:

Billboard Hot Country Top 10 (Jan. 15, 2005)

* Both Wilson and Rimes' songs were about men, but fit the "opposite sex" theme.

Billboard Hot Country Top 10 (Aug. 24, 2013)

Billboard Hot Country Top 10 (Jan. 24, 2015)

* "Sun Daze" includes a reference to a motorcycle, not a truck.

Lyrics about the opposite sex have always been prevalent, and while today's songs are much more misogynist and sexual in nature, that category is mostly a wash between now and then.

More than anything else, there is an undeniable trend that has taken the radio by storm: Trucks and booze.

The 2005 chart featured one song referencing trucks, two referencing alcohol and one more referencing both (Blake Shelton's "Some Beach"). Compare that to the height of bro madness in 2013, when five songs referenced both categories, plus one solo reference for each (trucks in Randy Houser's "Runnin' Out of Moonlight" and alcohol in Keith Urban's "Little Bit of Everything").

It's only gotten more out of hand.

The current Top 10 features nine songs that refer to alcohol. Seven of them refer to trucks, with seven total referencing both. Only Carrie Underwood ("Something In the Water") steered clear of both categories.

We know the formula works, as evidenced by a recent viral video that mashed together six hit country songs into one chart-topping beast: