A.4.1 Orders and revenue by region
Positive currency translation effects added one percentage point each to order and revenue growth; portfolio transactions had only minimal effects on volume growth year-over-year. The resulting ratio of orders to revenue (book-to-bill) for Siemens in fiscal 2019 was a strong 1.13, again well above 1. The order backlog was € 146 billion as of September 30, 2019, a new high.
1 As defined by the International Monetary Fund.
Orders related to external customers were clearly up year-overyear on growth in nearly all industrial businesses, led by Mobility. Gas and Power, Siemens Healthineers, Smart Infrastructure and SGRE all posted clear growth, while orders declined slightly in Digital Industries. Volume from large orders for Industrial Businesses overall was up substantially due to a sharp increase at Mobility, but also due to a significant increase in SGRE and Gas and Power. Growth in emerging markets was driven by orders from China, and from Russia where Mobility won a € 1.2 billion contract for high-speed trains including maintenance.
Order development was mixed in the Europe, C. I. S., Africa, Middle East region. The majority of industrial businesses posted order growth, led by double-digit growth in Mobility, which won several large contracts in the year under review. This increase was more than offset by a substantial decline in SGRE due mainly to a lower volume from large orders and a decrease in Digital Industries. In contrast to the region overall, orders were up clearly in Germany, driven by sharp growth in Gas and Power which recorded, among others, a large high voltage direct current (HVDC) order. Mobility recorded a significant increase in order intake in Germany, while the other industrial businesses posted declines.
Orders in the Americas region were up significantly year-over-year, benefiting from positive currency translation effects. Double-digit growth in nearly all industrial businesses was led by SGRE and Mobility with particularly sharp increases. The pattern of order development in the U. S. was largely the same as in the Americas region.
In the Asia, Australia region, orders also rose significantly due to growth in nearly all industrial businesses. The primary growth driver was SGRE, which recorded a sharply higher volume from large orders, including two large orders for offshore wind-farms
including service in Taiwan totaling € 2.3 billion. Orders for Mobility dropped substantially compared to the prior year. Clear growth in China included a majority of industrial businesses.
Table:
 |  | Fiscal year |  | % Change
(in millions of €) | 2019 | 2018 | Actual | Comp.
Europe, C. I. S., Africa, Middle East | 46,086 | 46,495 | (1)% | (1)%
therein: Germany | 12,021 | 11,254 | 7% | 7%
Americas | 29,812 | 25,060 | 19% | 14%
therein: U.S. | 21,166 | 18,106 | 17% | 10%
Asia, Australia | 22,101 | 19,742 | 12% | 11%
therein: China | 8,989 | 8,459 | 6% | 6%
Siemens | 97,999 | 91,296 | 7% | 6%
therein: emerging markets1 | 31,720 | 30,564 | 4% | 4%


Question: What drove the growth in the emerging markets?
Answer: Growth in emerging markets was driven by orders from China, and from Russia where Mobility won a € 1.2 billion contract for high-speed trains including maintenance.