Here's a short story:

Cardiff is the capital and largest city in Wales and the eleventh-largest city in the United Kingdom. The city is the country's chief commercial centre, the base for most national cultural and sporting institutions, the Welsh national media, and the seat of the National Assembly for Wales. The unitary authority area's mid-2011 population was estimated to be 346,100, while the population of the Larger Urban Zone was estimated at 861,400 in 2009. The Cardiff metropolitan area makes up over a third of the total population of Wales, with a mid-2011 population estimate of about 1,100,000 people. Cardiff is a significant tourist centre and the most popular visitor destination in Wales with 18.3 million visitors in 2010. In 2011, Cardiff was ranked sixth in the world in National Geographic's alternative tourist destinations. 

The city of Cardiff is the county town of the historic county of Glamorgan (and later South Glamorgan). Cardiff is part of the Eurocities network of the largest European cities. The Cardiff Urban Area covers a slightly larger area outside the county boundary, and includes the towns of Dinas Powys and Penarth. A small town until the early 19th century, its prominence as a major port for the transport of coal following the arrival of industry in the region contributed to its rise as a major city. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: What county is Cardiff in?
Guess: Wales and the United Kingdom.
Confidence: <appropriate level of confidence in this guess>

Question: Is Glamorgan in a historic area?
Guess: yes
Confidence: <appropriate level of confidence in this guess>

Question: What European group is Cardiff in?
Guess: the United Kingdom
Confidence: <appropriate level of confidence in this guess>

Question: What is the group of large European cities called?
Guess: the Eurocities network
Confidence: <appropriate level of confidence in this guess>

Question: Is Penarth in the Cardiff Urban Area?
Guess: yes
Confidence: <appropriate level of confidence in this guess>

Question: Can you name another town that is as well?
Guess: Dinas Powys
Confidence: <appropriate level of confidence in this guess>

Question: Was Cardiff always a large city?
Guess: no
Confidence: <appropriate level of confidence in this guess>

Question: When did it start to become so?
Guess: early 19th century
Confidence: <appropriate level of confidence in this guess>

Question: Did the industrial revolution have anything to do with this?
Guess: yes
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: What was its port used for?

coal