"fall markedly" is correct and usable in written English.
You can use it when referring to a decrease or drop in size, strength, or intensity. For example: "Market confidence has fallen markedly since the announcement of the new tax reforms."
And even though the level of violence did fall markedly during the week, Sheik Ahmed Yassin, the Hamas spiritual leader, immediately announced: "The resistance will continue.
The second death came after the number of fresh confirmed and suspected casualties in the outbreak had peaked and began to fall markedly.
Widespread expectations that house prices will continue to fall markedly for some considerable time to come is also significantly limiting housing market activity, as is heightened concern over the economic outlook and job prospects," he said.
"If the post-election fiscal consolidation is implemented, then the UK's fiscal deficit should fall markedly further in coming years, with a surplus in prospect towards the end of the decade.
"On top of this, faster rising unemployment, heightened concerns over the economic outlook, and widespread expectations that house prices will continue to fall markedly seem set to depress housing market activity and prices for some considerable time to come".
If the rate does not fall markedly this week as the plan is put into effect, it could signal a continuation of the credit crisis that has gripped the markets for much of the year and spell fresh trouble for stock prices, Mr. Yardeni said.
Measures of business and consumer confidence have fallen markedly.
Oil fell markedly, with Brent Crude futures down almost 3% at $107.29 a barrel.
At the industry's strongest banks, employee compensation, on average, fell markedly from a year ago.
In the female, the excretion of estrogens (female sex hormones) falls markedly at the menopause.
GDP growth projections have fallen markedly across the region, but nowhere near the levels seen during the 2008-9 financrisisrisis.
