pre_text: * Recast to reflect segment changes. Global Technology Services revenue decreased 0.2 percent as reported (1 percent adjusted for currency) in 2018 compared to the prior year, with Infrastructure & Cloud Services up 0.8 percent as reported (flat adjusted for currency) offset by a decline in Technology Support Services. In Infrastructure & Cloud Services, the business focused on prioritizing the portfolio to deliver high-value solutions to bring productivity to clients and allow for expanding workloads, while it exited some lower-value offerings. Technology Support Services was impacted by the hardware product cycle dynamics in 2018 but grew its multivendor services offerings. Within GTS, cloud revenue of $8.0 billion grew 22 percent as reported and 21 percent adjusted for currency compared to the prior year.
table: ($ in millions)
table: For the year ended December 31: 2018 2017 Yr.-to-Yr. Percent Change Yr.-to-Yr. Percent Change Adjusted for Currency
table: Global Technology Services external revenue $29,146 * $29,213 * (0.2)% (0.8)%
table: Infrastructure & Cloud Services $22,185* $22,016* 0.8% 0.0%
table: Technology Support Services 6,961 7,196 (3.3) (3.5)
question: Analyse this data from a financial earnings document. What is the average of Global Technology Services external revenue for the year 2018 and 2017