 component is present in an amount of from {HEAD ~ about 99 to about 1 percent} by {TAIL ~ weight} based on the combined quantities of components and  
by
component is present in an amount of from { HEAD ~ about 99 to about 1 percent } by { TAIL ~ weight } based on the combined quantities of components and
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH