By John S. McClenahen U.S. small business registered its nineteenth consecutive month of 100-plus growth on the National Federation of Independent Business' (NFIB) "optimism" index in October. But at 103.9, October's index figure was six-tenths of a percentage point below September's mark. The percentage of companies expecting to increase their capital spending rose two points to net 34%. However, the percentage of companies expecting business conditions to improve during the next six months fell by six points to net 30% in October, and a net 22%, down a percentage point from September, foresaw higher sales. The percentage of companies planning to add jobs rose one percentage point to a net 15%.