The phrase "at historical levels" is correct and usable in written English.
It can be used when discussing data, statistics, or trends that are comparable to past measurements or benchmarks.
Example: "The unemployment rate has dropped to at historical levels not seen since the early 2000s."
Alternatives: "at record levels" or "at previous levels".
The initial water tests seem to back up Bennett's claims, with samples showing mercury and other toxic substances at historical levels.
Mortgage rates could be well under 3 percent, if the gains banks make when they sell the mortgages were at historical levels, according to an analysis by The New York Times this year.
Our intent is to continue to recruit at historical levels — 30 to 35 tenure-track positions per year".
My colleagues and I attempted to convince them that those jobs simply will not exist again, at historical levels of compensation, in the months or years before these students' graduation.
It makes it worse, at a time when the number of long-term unemployed Americans is at historical levels.
Interest rates remain at historical levels but we know that even threatened increases in 2016 will have a nominal effect on our bottom line.
With interest rates and inflation at low historical levels, any increase in rates would cut the price of bonds.
It is noteworthy that the levels of inflow and outflow rates are back at their historical levels.
Further, as TrimTabs points out, the available float of telecom stocks is not only shrinking, but is also at low historical levels.
As part of their response to the crisis, Californian officials are signing long-term contracts to buy power at prices several times historical levels: at the new level, even fuel cells can compete.
"When we picked things up in mid-2002 and 2003, it would not have been prudent, given market conditions, to have maintained distribution at the same historical levels," he said.
