More than one in five of the UK's top 50 law firms have seen their fee income grow by at least 50% over the last five years, according to Legal Week's analysis of firms' financial performance.

The analysis, which spans the period from 2008-09 through to 2013-14, shows the pace and extent of growth at the upper end of the market, with six firms seeing at least an 80% rise in revenue. Of the 46 firms for which a full five-year comparison was possible, only seven brought in less in fee income in 2013-14 than five years previously, meaning 85% of firms grew in that period.

Consolidation was responsible for much of the growth, with the transformative tie-ups undertaken by several of the top 50 in the past half-decade reflected in exponential growth in turnover.

DWF has made the biggest leap forward in revenue terms, more than tripling its fee income from £61m in 2008-09 to £191m last year. The ambitious firm has embarked on a spree of mergers in recent times, with four tie-ups over the last two years alone, in addition to the acquisition of collapsed firm Cobbetts in February 2013.

Despite significantly increasing headcount, DWF also achieved the fourth largest profit per equity partner (PEP) increase over the five-year period, growing average PEP by 78% from £230,000 to £411,000. Only Shoosmiths, Travers Smith and Eversheds have registered higher percentage rises in PEP since 2009.

Mishcon de Reya placed second in terms of revenue growth, with a 121% increase from £47.3m to £104.6m. 

Those firms that have undergone transformative mergers since 2009 inevitably feature prominently in the list of best performers over the period. These include Clyde & Co, which has increased turnover by 97%, Ashurst (95%), Herbert Smith Freehills (80%) and DAC Beachcroft (65%).

Clydes chief executive Peter Hasson says that its 2011 tie-up with legacy Barlow Lyde & Gilbert, a firm with revenue of around £90m at the time of the deal, was only part of its growth story. "Some of the trends in the market have been fortunate for us," explains Hasson. "Globalisation, the rise in the commodities market, growth in Asia – these have all been factors that have favoured us."

Firms that have not merged but still posted revenue hikes of more than 40% include Travers Smith (51%), TLT (49%), Holman Fenwick Willan (46%), Stephenson Harwood (42%) and Macfarlanes (41%), although it is worth noting that 2008-09′s results would have been affected by the financial crisis.

Sharon White, chief executive at Stephenson Harwood, says: "We are proud of what we've achieved as we haven't done it through a merger. It's all been organic growth, albeit some from laterals. We've never had a dip in revenue so we've maintained good growth throughout this tough period."

Among the magic circle firms, five-year changes in revenue have been more modest. Freshfields Bruckhaus Deringer and Linklaters even saw dips in turnover of 4.3% and 3.3% respectively. Allen & Overy (A&O) has grown the most since 2008-09, with a 13.1% revenue rise and a 12% hike in PEP.

"If you look at the market as a whole it's tricky because the demand for legal services has not grown in the same way over that five-year period as it had previously," says A&O managing partner Wim Dejonghe. "So if you have hardly any growth or none since the financial crisis you have probably done alright, and we've had 13% growth over that period so we have taken market share.

"We have improved our footprint while other firms haven't. The other element that is underestimated is the alternative delivery model, which has also helped grow the business." 

However, over a longer 10-year period, the magic circle firms have, taken as a whole, increased combined fee income by 62%. 

A&O logged the biggest uptick, growing 89% from £652m in 2003-04 to £1.2bn in the last financial year. Linklaters has seen a 74% rise over the same period, with Freshfields up by 57%.

Click here to view the full table of the top 50 results

Full coverage of Legal Week's UK top 50 coverage can be found here