By Richard Horgan Los Angeles (Knewz) — According to Care.com’s latest annual “Cost of Care” survey, the weekly rate for a nanny last year ranged in the highest 10 states from $706 to $855. Topping the list is the District of Columbia, followed by the states of Washington ($840) and Massachusetts ($834). D.C. was even further ahead of the pack when it comes to daycare costs, topping the list at $419 per week, ahead of once again the same two states but in reverse order: Massachusetts ($324) and Washington ($304). The data was compiled by surveying 3,003 parents across the U.S. paying for child…