To estimate machinery noise EN 12354-5 provides methods for airborne and structure-borne sound transmission. For the latter the source and receiver mobility need to be considered. In the current revision a general case is described that allows any mobility ratio. This formulation uses the structure-borne sound power as input quantity for prediction to account for the coupling between source and receiver. The global transmission can therefore be described as the ratio between the spatial average sound pressure level in a room and the structure-borne sound power of the source connected to a building element and is defined in ISO 10848 as level difference D_TF. This quantity can be calculated or measured. In case of a measurement each transmission situation seems to be unique in the first place. Nevertheless in previous work it was presented for timber buildings, that the spread of data can be reduced when grouping similar constructions and paths. In recent years data was continuously collected in field measurements. This paper presents the analysation of this data set with the aim to derive average values of groups that can be used for prediction.