Higher prices and reduced chances of winning prizes have proven to be a turn-off for Lotto players as overall sales of all National Lottery games fell by 2.5 per cent last year.

The new 47-ball format introduced last September reduced the odds of winning and an increase in the minimum cost of playing Lotto from €3 to €4 has weighed on the company’s fortunes.

New figures show the percentage of Ireland’s adult population playing National Lottery games on a regular basis has decreased from 44 per cent in 2014 to 42 per cent last year – a reduction of around 67,000 players on average.

The first full-year financial results for the National Lottery since the franchise was taken over by Premier Lotteries at the end of November 2014, show total sales figures fell from €687.7 million in 2014 to €670.4 million last year. Falling sales occurred despite the upturn in the economy and an expansion of the Lotto agent network by over 300 to 4,002 outlets.

In tandem with reduced turnover, the amount donated to “good causes” also fell by 3.4 per cent or €6.6 million to €188 million in 2015.

Under the licence to operate the National Lottery, 65 per cent of gross revenue, which is sales less prizes, is paid to fund good causes.

In a report to the Regulator of the National Lottery, the company said it was focused on “growing sales, offering players a wide choice of games and maximising the amount raised for good causes.”

It welcomed a 61 per cent increase in numbers using online games with interactive players growing from 140,000 to over 225,000 by the end of 2015.

The Times revealed earlier this year that the number of players winning any type of prize in the twice-weekly Lotto and Lotto Plus draws had fallen sharply since the new game format was introduced last September.

At the same time, an analysis of almost 120 draws under both the new and old formats showed the average prize fund for each play under the 47-ball game had only increased by 3.6 per cent, despite the 33 per cent rise in the cost of playing.

It showed that an average of only 66,700 players win some type of prize on each draw night under the new format, compared with more than 93,000 under the old 45-ball game.

The introduction of the 47-ball format was the first major change to the structure of the Lotto since 2006.

Although there are now bigger jackpot prizes, the chances of scooping the top prize have lengthened from 1 in 8.1 million to 1 in 10.7 million as a result of the use of two additional balls in Lotto draws.

Extra winning combinations were added to the main Lotto draw as well as a €300 raffle prize for Lotto Plus players.

Last night, a National Lottery spokeswoman said Premier Lotteries had faced a challenging retail environment in 2015 but that it had still been “a year of considerable growth, development and investment.”

The company said it had provided “a much needed refresh of the game portfolio to ensure that players have exciting and engaging games.”

The spokeswoman said sales so far in 2016 were “much improved” and were running 8 per cent ahead of the corresponding period last year.

She pointed out that the highest weekly sales recorded since 2010 had occurred in January.