Feature usage statistics

I've created some custom features, registered descriptors for them via implementing ProductivityFeaturesProvider interface. Now I would like to read usage statistics via

final FeatureDescriptor descriptor = productivityFeaturesRegistry.getFeatureDescriptor(featureId);

but I receive descriptor without updated statistics (i.e. usageCount is different than value in Help > Productivity Guide dialog). I investigate a little and it turns out that feature usage statistics are persisted via FeatureUsageTrackerImpl in feature.usage.statistics.xml. Until I use some tracked feature or open Productivity Guide I do not receive valid statistics. What should I do to receive valid usage statistics?