The phrase "a fall of only" is correct and usable in written English.
It can be used to describe a decrease or reduction in a specific quantity, often in a context where the decrease is considered minor or insignificant.
Example: "The stock market experienced a fall of only 2% today, which is relatively stable compared to previous weeks."
Alternatives: "a drop of just" or "a decrease of merely".
The total number of people who reached Italy from Africa between January and 23 August this year was 98,072, according to the International Organization for Migration (IOM), the UN migration agency – a fall of only 7,000 from the same period last year.
Although the IMF talks optimistically of a fall of only 10% this time, she predicts falls of 15% this year and another 5% in 2014.
It also found 51% of white people thought the criminal justice system either treated black people fairly or was even biased in their favour – a fall of only two percentage points since 2013.
A good piece in the US's Financial Times the other day (beware the paywall) explained that listenership is down from 60 million "at least once a week" to below 50 million, revenues 7% down compared to a fall of only 1.25% for music stations.
Visits from the Eurozone dropped by an even smaller proportion, recording a fall of only 5.6 per cent.
In one section, the winding route between the Pont du Gard and St Bonnet required an extraordinary degree of accuracy from the Roman engineers, who had to allow for a fall of only 7 mm per 100 m of the conduit.
How odd that Portugal in March expected a 2001 figure of only 2.2%.
It had actual sales of $18.4 compared to a 1984 projection of only $8 million.
Instead of aiming for 100%, the Environment Agency set out nationally to achieve a "good" target in 2015 of only 31% of water bodies.
It left the industry with an average occupancy rate last year of only 60%.
However, influenza is a difficult surveillance target, with an accuracy of clinical diagnosis in 1968 of only ≈66% (40 ).
