This article originally appeared on REMODELING's sister site, REPLACEMENT CONTRACTOR.

Most replacement contractors went into 2017 feeling optimistic about sales growth, but new data may eclipse even the sunniest of expectations.

Replacement contractors comprising the 2018 Remodeling 550 reported a blistering 2017 sales growth of 41% over 2016. Collectively, replacement contractors took in $3.88 billion last year, Remodeling magazine revealed today. That figure far surpasses any other sales in the past 10 years — including the boom years.

And 2018 sales are projected to be even bigger. Replacement Contractors are projecting a whopping $4.72 billion in sales this year, according to the Remodeling 550 data. That’s a 22% percent increase over 2017’s already record-breaking haul.

The 10 biggest replacement contractors accounted for the lion’s share of the sales, with 53% of all revenue in 2017. That $2.04 billion was 54% above what the same 10 biggest contractors said they achieved the previous year when sales were $1.3 billion. By comparison, the bottom third of the replacement contractors accounted for only 4% of all sales or $151.71 million in 2017.

The Remodeling 550 membership varies a bit each year as companies enter and exit the list for a variety of reasons, such as if they were bought or began to be publicly traded.

Replacement Contractor will be revealing more data in future Remodeling 550 previews. The list and full report will go online May 23.