Asda has been crowned the cheapest supermarket for the ninth year in a row.

The retailer has once again dominated the pricing tables for the past 12 months and claimed The Grocer 33's lowest priced shopping basket for 30 of the past 50 shops conducted for the survey throughout the course of the year.

The contents of The Grocer 33's shopping basket are rotated on a regular basis and last year we checked the prices of ten separate baskets. This year we increased the frequency of basket changes to 13, meaning that no basket ever remained the same for more than four weeks.

At the end of every period we create a table which shows each retailer's average basket price for the period. As the table above shows, Asda has also claimed the cheapest average shopping basket for nine of the 13 different baskets compiled over the last 12 months.

In second place was Tesco. The retailer has been competing fiercely on price and, as the chart above shows, has yielded the cheapest average shopping basket on three separate occasions this year. Tesco has displayed a renewed intent on closing the pricing gap between itself and Asda over the past few months. While it has claimed The Grocer 33's cheapest shopping basket for just 14 of the last 50 shops, 10 of these have been in the last six months since January.

Sainsbury has also been busy hammering down prices. The retailer managed to claim The Grocer 33's cheapest average shopping basket for the five-week period between 20 August and 17 September.

But if the battle for third place was fiery last year, it's positively explosive now. Morrisons and Sainsbury remain locked in a furious battle to seize the bronze. And while Morrisons has only been The Grocer 33's cheapest supermarket for two of the 50 shops conducted this year compared with Sainsbury's four, The Grocer 100 data shows Sainsbury still has a way to go before it can leave Morrisons behind.

Somerfield in recent weeks has claimed to be driving down prices, but The Grocer 100 reveals that its basket is still 14.75% more expensive on average than Asda.

Next week we will be making yet another dramatic change to the way in which The Grocer 33 is produced when we introduce the first ever weekly rotating shopping basket.Customer Service

Providing full shelves is only half the battle. There is no room for half-hearted customer service in today's hyper-competitive retail environment and stores must fulfil an ever-widening range of criteria to keep their shoppers happy. This is the responsibility of store managers. It's a tough job but one which Morrisons managers take in their stride, which is why we have devoted this section to them. Morrisons has claimed The Top Store Award 12 times this year.The Grocer 100 Index

Asda has picked up the award for the lowest-priced supermarket for the ninth year in a row - but only just.

The strong inflationary trend across the industry since the early part of 2006 has caused grocery prices to jump quite considerably, particularly in the past month, as the chart above and the results of last week's The Grocer Price Index illustrate.

At £169.46, the cost of Asda's basket for the full year is 1.1% more expensive than in our 2005 End of Year Review, despite Asda president Andy Bond's Christmas pledge to widen the gap with its competitors and be more aggressive on price.

Asda's basket reached its lowest point for the year in early January when it cost just £165.22 before soaring up to £173.39 by the end of March. Our chart above shows that Asda's average basket price for year is now just 0.7% cheaper than Tesco's.

The gap between the top two supermarkets has narrowed drastically since our last report 12 months ago when Asda had proved 1.8% cheaper than Tesco for the year, and closer inspection of The Grocer 100 data also shows that Tesco is currently beating Asda for price. The cost of Asda's secret shopping basket of goods stands at £174.88 this week compared with Tesco's at £172.84. There was also a four-week period in March when Tesco was quite extensively cheaper than its rival.

Tesco's basket has remained largely unaffected by the industry's fluctuations. Last June, Tesco's average basket price for the full year cost £170.64. Twelve months on and our latest results show its basket is now £170.66 - just 2p more expensive.

Morrisons came third in terms of pricing according to The Grocer 100. Its average basket price of £173.62 for the year is now just 2.45% higher than Asda's compared with 4% last year. The average cost of Morrisons' basket rang in 61p cheaper than it did a year ago. As the graph above also shows, the competition between Sainsbury and Morrisons has continued to intensify over the year as Sainsbury has tightened its grip on price.

In the last End Of Year Review we found that Sainsbury had been 6.2% more expensive than Asda. It has now narrowed the gap with Asda to 3.2%. It has also been just 0.75% more expensive than Morrisons for the year, and the yellow and red lines on our graph appear to merge entirely as they reach June.