But since the toughest packaging rules are in Australia, that may be worth looking at:
https://en.wikipedia.org/wiki/Plain_tobacco_packaging
In 1973, Australia's first health warning on cigarette packages appeared with the simple message 'WarningSmoking is a health hazard'.[3] Since 1 March 2006, graphic images depicting the effects of smoking cigarettes have been required to be displayed on cigarette packets. Warnings must cover 30% of the front and 90% of the back of the box.[4] The 10% of the back not occupied by a warning is used for the message "Sale to underage persons prohibited".
Since 1 December 2012 all forms of branding logos, colours, and promotional texts are banned from cigarette pack designs. The requirement is for plain cigarette packaging showing only brand name and health warning messages. Australia is the first country in the world to have plain packaging cigarette packs.[5][6]
Canada was the first country to use graphic pictures in conjunction with written warnings on cigarette packages, with the legislation coming in 2000.[7]
https://en.wikipedia.org/wiki/Cigarette_packets_in_Australia
We do have the figures for 2000, 2005, 2010 and 2012 from your source, so, looking at those 2 countries and the UK and USA:
Australia 27 23 20 18
Canada 29 25 21 20
UK 31 27 23 22
USA 28 25 22 21
So smoking is decreasing at a slightly faster rate (down 9% in 12 years, v. 7% for the USA) in the other sizeable English-speaking countries (relevant, since the cultures are fairly similar, and the tobacco companies are more likely to share brands and marketing across them). So there may be something to the packaging rules.