The survey provides volume and value data on international visitors to the UK, including Wales.
This is the latest release
The International Passenger Survey conducts between 700,000 and 800,000 interviews a year of which over 250,000 are used to produce estimates of Overseas Travel and Tourism.
Interviews are carried out at all major airports and sea routes, at Eurostar terminals and on Eurotunnel shuttle trains.
Office for National Statistics website: International tourism
VisitBritain also provides comprehensive statistics on visits to the UK, including Wales, by overseas residents based on data from the IPS.
VisitBritain website: Insights & Statsitics
The VisitBritain website includes excel pivot tables which can be downloaded to provide information for each UK Nation/region, including one for Wales, showing overseas residents' visits, nights and spend data from 2002 to 2012.