If you specify a negative scale, Oracle Database rounds the actual data to the specified number of places to the left of the decimal point. For example, specifying (7,-2) means Oracle Database rounds to the nearest hundredths, as shown in Table 26-1.
McCann (2000) found that households in communities with good transit use save an average of about $3,000 annually on transportation costs. Litman (2004) found annual transportation cost savings of about $1,300 per household in cities with well-established rail transit systems compared with cities that lack rail.
Though they vary significantly, transportation costs accounted for 40% of the average overall cost of coal delivered at electric power plants in 2010. On average, nominal U.S. rail rates for shipping coal grew from $11.83 to $17.25 per short ton from 2001 to 2010.