The country A Consumer Price Index is approximated by the following​ formula, where t represents the number of years after 1990. A(t)=100e^0. 021t For​ instance, since​ A(16) is about 140​, the amount of goods that could be purchased for​ $100 in 1990 cost about ​$140 in 2006. Use the function to determine the year during which costs will be ​70% higher than in 1990