The figure on line 9 for qualified business expense deduction is not 20% of any other figure or combination of figures in my return--where did it come from?

How is the deduction for qualified business income computed?

A6. The SSTB limitation discussed in Q&A 5 does not apply if a taxpayer’s taxable income is below $315,000 for a married couple filing a joint return and $157,500 for all other taxpayers; the deduction is the lesser of:

       A) 20 percent of the taxpayer’s QBI, plus 20 percent of the taxpayer’s qualified real estate investment trust (REIT) dividends and qualified publicly traded partnership (PTP) income

     B) 20 percent of the taxpayer’s taxable income minus net capital gains.

If the taxpayer’s taxable income is above the $315,000/$157,500 thresholds, the deduction may be limited based on whether the business is an SSTB, the W-2 wages paid by the business and the unadjusted basis of certain property used by the business. These limitations are phased in for joint filers with taxable income between $315,000 and $415,000, and all other taxpayers with taxable income between $157,500 and $207,500. The threshold amounts and phase-in range are for tax-year 2018 and will be adjusted for inflation in subsequent years.