I've been looking into the GDP growth of financial markets relative to the Global growth in economic output and activity, though I've came accross these three international organisation, each provide a different set of growth rate for Global GDP, does anybody have any opinion on which one would have the most reliable methodology for use?

||IMF|World Bank|WTO|
|:-|:-|:-|:-|
|2019 Global GDP Growth|2.9%|2.4%|2.3%|
|2019 Trade Volume Growth|1.0%|1.4%|1.2%|

Since 2019 is just finished and the data may be preliminary but even their 2018 data are different from each other.

||IMF|World Bank|WTO|
|:-|:-|:-|:-|
|2018 Global GDP Growth|3.6 %|3.0 %|2.8 %|
|2018 Trade Volume Growth|3.7 %|4.0 %|3.0 %|

Here is where I've obtained the above figures:

IMF: [https://www.imf.org/en/Publications/WEO/Issues/2020/01/20/weo-update-january2020](https://www.imf.org/en/Publications/WEO/Issues/2020/01/20/weo-update-january2020)

World Bank: [https://www.worldbank.org/en/publication/global-economic-prospects](https://www.worldbank.org/en/publication/global-economic-prospects)

WTO: [https://www.wto.org/english/news\_e/pres19\_e/pr840\_e.htm](https://www.wto.org/english/news_e/pres19_e/pr840_e.htm)

Please help to advise me which would be best to use, or if you have an even better source, do share!

Thanks!