The phrase "are usually much lower" is correct and usable in written English.
It can be used when comparing quantities, values, or levels that are typically less than another reference point.
Example: "The costs associated with online courses are usually much lower than those of traditional classroom settings."
Alternatives: "tend to be significantly lower" or "are generally much less".
The overexpression yields of eukaryotic membrane proteins in E. coli are usually much lower than those of prokaryotic ones.
Brazil has many other couples like them, though pensions outside the public sector are usually much lower.
But they are usually much lower than the local loan shark's, and poor people seem generally happy to have a reliable source of finance.Increasingly, mainstream financial firms see money to be made.
But don't assume the federal government will pay all of your expenses; many storms do not qualify as disasters, and payments are usually much lower than what an insurance policy would reimburse.
Whereas midsummer temperatures may reach as high as 59 °F (15 °C) on the Antarctic Peninsula, those elsewhere are usually much lower, ranging from a mean of about 32 °F (0 °C) on the coast to between −4 and −31 °F (−20 and −35 °C) in the interior.
What often happens is that the taxable profit is shifted somewhere else - where taxes are usually much lower.
Post-synthesis loading of drug in tortuous pore structures like those seen here is usually much lower than that of MCM-41 due to the longer diffusion path41.
This study, based on a leading country in term of stomach cancer management, provides insightful results for other countries in which 'cure' fraction is usually much lower.
Besides the differences in the sizes of WBC and viruses, the concentration of the virus particles is usually much lower than WBC.
There is a registration tax, based on a government-calculated fiscal value that is usually much lower than the market value.
But the cost of insulating in the roof is usually much lower than the cost of solid wall insulation, so it is often more cost-effective to do the roof first.
