The amount of metal hydrate often ranges from about 3 percent, usually at least about 5 percent, and often at least about 10 percent, based on the total weight of that formulation; but {HEAD ~ the amount} of metal hydrate usually does not exceed {TAIL ~ about 35 percent}, often does not exceed about 30 percent, and frequently does not exceed about 25 percent, based on the total weight of that formulation 
The amount of metal hydrate often ranges from about 3 percent , usually at least about 5 percent , and often at least about 10 percent , based on the total weight of that formulation ; but { HEAD ~ the amount } of metal hydrate usually does not exceed { TAIL ~ about 35 percent } , often does not exceed about 30 percent , and frequently does not exceed about 25 percent , based on the total weight of that formulation
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