Table 1. Statistical information on dispersed oil including the number of filter papers used during a simulation of chainsaw operation for felling and pruning, the average amount of oil scattered per filter paper over 5 minutes, and the corresponding standard error.

	Number of filter paper	Average amount of oil (g/filter paper∙5min)	Standard error
Cluster 1	18	0.0328	0.0013
Cluster 2	20	0.0342	0.0018
Cluster 3	16	0.0306	0.0017
Cluster 4	12	0.0277	0.0025
Cluster 5	12	0.0278	0.0012
Cluster 6	11	0.0199	0.0009
Cluster 7	22	0.0298	0.0014
Cluster 8	21	0.0277	0.0006
Cluster 9	24	0.0277	0.0008