Rolling Total w/ Uneven Columns

[taskinosurname]

Hello Everyone,

I'm still getting a hang of Dax, and every now and then I run into issues I haven't been able to find online. I'm hoping for a little assistance. My goal is to create a rolling collision rate (per 100,000 KM). Of course, this was easy in excel, but the issue I'm having with Dax is that it's giving me random numbers before March 2021 (i.e. please see columns "R12MDistance"). The Dax I used for each column were:

R12MDistance = 
Var _MaxDate = MAX('Date'[Date])
Var Result =
    CALCULATE(
        [TotalMonthlyDistance], 'Date'[Date] <= _MaxDate,
        ALL('Date')
    )
Return
Result

R12MDistance v2 = 
VAR MaxDate = MAX('Date'[Date])    
VAR MinDate = EDATE(MaxDate, -12)   
VAR Result = 
     CALCULATE(
          [TotalMonthlyDistance],
          FILTER(ALL('Date'),    
          'Date'[Date] <= MaxDate &&  
          'Date'[Date] > MinDate)  
     )
RETURN
     Result

R12MDistance v3 = 
CALCULATE(
[Total Monthly Distance], DATESINPERIOD('Date'[Date], MAX('Date'[Date]),-12,MONTH)
)

Since there are no recorded KM before March 2021, what I want is for the first distance running total to be  567564 KM then start adding the months after.

Ultimately the formula would end up looking like this:

R12MCollisionRate =
Divide([R12MPreventable],[R12MDistance])*100000

Below is a snippet of the data I'm working with. Thank you for your time and assistance.

Year	Month	PreventableWithZero	R12MPreventable	TotalMonthlyDistance	R12MDistance	R12MDistance v2	R12MDistance v3
2020	April	1	19		2527252
2020	May	2	19		2617511
2020	June	1	20		2707770
2020	July	4	24		2798029
2020	August	1	24		2888288
2020	September	0	24		2978547
2020	October	1	22		3068806
2020	November	0	19		3159065
2020	December	1	17		3249324
2021	January	0	15		3339583
2021	February	2	13		3429842
2021	March	1	14	567564	25655097	12486408	6810768
2021	April	0	13	515028	46914040	23817024	12991104
2021	May	0	11	481293	67819904	34405470	18766620
2021	June	0	10	516411	91163310	47846808	24963552
2021	July	0	6	459690	113100535	55879692	30479832
2021	August	0	5	445834	135347476	65688040	35829840
2021	September	0	5	469338	159543765	76013476	41461896
2021	October	0	4	436720	183178302	85621316	46702536
2021	November	0	4	481630	209797049	100590684	52482096
2021	December	0	3	433599	235073568	105756354	57685284
2022	January	1	4	404657	259799127	114658808	62541168
2022	February	4	6	398315	285016900	129031817	67320948
2022	March	0	5	510614	316758552	134655246	66637548