Payroll firm Automatic Data Processing said the US economy added 215,000 non-farm private sector jobs in December, far more than economists expected. Following a gain of 118,000 jobs in November, which was below average for 2012, the job market picked up steam with small businesses adding 25,000 jobs, medium-sized businesses -- 50 and 499 employees -- adding 102,000 and larger businesses adding 87,000 jobs. ADP President and Chief Executive Officer Carlos Rodriquez said U.S. private sector employment \"ended the year on a positive note.\" December posted the largest one-month jump in jobs since February 2012, he said. On average, U.S. employers added 144,666 private sector jobs per month in 2012 with the peak in February with 227,000 jobs added and the low point in May when 81,000 jobs were added.