In some cases the report displays the value undefined in cells:

• Pick "Spenden/Stornos pro Monat" from the report list
• Pick timeframe of 2017-07-26 to 2017-08-08
• Pick campaign 03-ba-170804 and all related keywords

The response from the server looks like this:

{
	"2017-08": {
		"donations": {
			"0": 3152,
			"3": 42,
			"6": 28,
			"12": 48,
			"1": 97
		},
		"cancellations": {
			"12": 2
		}
	}
}

There are keys missing in cancellations.