Forecast in Qliksense

[jshashiv]

Hello

I am looking for forecast in Qliksense. We have data of ticketing system which get logged everyday. Data is from JAN-19 to NOV-19 as below

tick_num	EXTRACTDATE	Month-Year
TKTC43680038	01-01-2019	Jan-2019
TKTC43679855	01-01-2019	Jan-2019
TKTC43674879	01-01-2019	Jan-2019
TKTC43694599	02-01-2019	Jan-2019
TKTC43694844	02-01-2019	Jan-2019
TKTC43692921	02-01-2019	Jan-2019
TKTC43687443	02-01-2019	Jan-2019
TKTC43715566	03-01-2019	Jan-2019
TKTC43714367	03-01-2019	Jan-2019
TKTC43712006	03-01-2019	Jan-2019

I used below formula to calculate forecast.

=if(Count(tick_num),Count(tick_num), linest_m(total aggr(if(Count(tick_num),Count(tick_num)),[EXTRACTDATE.autoCalendar.YearMonth]),[EXTRACTDATE.autoCalendar.YearMonth])*

only({1}[EXTRACTDATE.autoCalendar.YearMonth]) +linest_b(total aggr(if(Count(tick_num),Count(tick_num)),[EXTRACTDATE.autoCalendar.YearMonth]),[EXTRACTDATE.autoCalendar.YearMonth]))

After DEC-19 , I am getting the forecast values in minus as below. Is their anything wrong I am doing in above formula as I m getting minus values in forecast. Please help me. Thanks in advance.

Jan-2019	3215
Feb-2019	2574
Mar-2019	2857
Apr-2019	3053
May-2019	3180
Jun-2019	2120
Jul-2019	1176
Aug-2019	853
Sep-2019	899
Oct-2019	875
Nov-2019	759
Dec-2019	244.65148717654
Jan-2020	-46.375797834771
Feb-2020	-337.40308284614
Mar-2020	-609.65441398579
Apr-2020	-900.6816989971
May-2020	-1182.3210070726
Jun-2020	-1473.3482920839