Usage summary for all months

Report with number of used seats, aggregated per month.

GET /reports/usage
[
{
month: { month: 10, year: 2018 },
numUsedObjects: 31633,
numFirstBookings: 8775,
numFirstBookingsByStatus: {booked: 8100, reserved: 675},
numFirstBookingsOrSelections: 31633
},
{
month: { month: 11, year: 2018 },
numUsedObjects: 87678,
numFirstBookings: 5742,
numFirstBookingsByStatus: {booked: 3245},
numFirstBookingsOrSelections: 87678
},
]