Returns outbound call totals per day for a date range, as the Daily Calls report in the portal: number of calls, successful (billable) calls, total duration in seconds, total cost, ASR (percent) and ACD (seconds), plus totals for the whole range. Days are calendar days (UTC); without time_range the last week is returned and a range can span at most 1 year. Results can be narrowed by SIP account and destination country (ISO 3166-1 alpha-2 code).