pre_text: The Systems gross profit margin decrease year to year was driven by the mix away from IBM Z and margin declines in Power Systems and Storage Systems. The pre-tax income decline was driven by the strong performance in IBM Z in the prior year and the continued investment in innovation across the Systems portfolio.
table: ($ in millions)
table: For the year ended December 31: 2018 2017 Yr.-to-Yr. Percent/ Margin Change
table: Systems
table: External Systems Hardware gross profit $2,590 $2,893 (10.5)%
table: External Systems Hardware gross profit margin 40.7% 44.6% (3.8)pts
table: External Operating Systems Software gross profit $1,412 $1,469 (3.9)%
table: External Operating Systems Software gross profit margin 84.5% 86.4% (1.9)pts.
table: External total gross profit $4,002 $4,362 (8.2)%
table: External total gross profit margin 49.8% 53.2% (3.4)pts.
table: Pre-tax income $ 904 $1,128 (19.9)%
table: Pre-tax margin 10.2% 12.6% (2.4)pts.
question: Analyse this data from a financial earnings document. What is the increase/ (decrease) in External Systems Hardware gross profit from 2017 to 2018