. Kent Co. includes one coupon in each bag of dog food it sells. In return for eight coupons, customers receive a leash. The leashes cost Kent $2.00 each. Kent estimates that 40 percent of the coupons will be redeemed. 500,000 and 600,000 bags of dog food were sold in 2006 and 2007, respectively. 18,000 and 22,000 leashes were purchased in 2006 and 2007, respectively. 120,000 and 150,000 coupons were redeemed in 2006 and 2007, respectively. The estimated liability for premiums at December 31, 2006 is