The average credit card interest rate is 21.09 percent. APRs on most new credit card offers are still at a historic high, according to CreditCards.com’s latest Weekly Rate Report. Among the 100 cards tracked weekly by CreditCards.com: Over half of new card offers still start APRs well above 20 percent. More than a third only offer APRs at 21.24 percent or higher. Nearly all new card offers — 87 out of 100 offers — currently start APRs at 17.99 percent or more. Until last year, by contrast, the highest weekly APR average CreditCards.com had ever recorded was 17.8 percent. But at least one major lender shifted course this week, selectively trimming the starting APR on a co-branded card for motorcycle enthusiasts. As a result, the average APR for brand-new cards slipped Wednesday for just the fifth time in a year. Both U.S. Bank and Barclaycard widened APR ranges on select offers At least two bank card issuers were active this week. U.S.…