grafana: singlestat percentages for time selected

Question

I am using:

• Grafana - 4.4.3
• Graphite - 0.9.12

my goal is to have 3 singlestats:

1. visitors
2. registrations
3. percentage of visitors becoming registrations.

for selected timeframe I have 2 singlestats:

1. site visitors sumSeries(stats.counters.$server.visitors.count)
2. site registrations sumSeries(stats.counters.$server.registrations.count)

both works great, displays 1 number respectively and correct.

Now I want to add 3rd singlestat that should be the percentage of registrations for that timeframe basically something like this:

A: sumSeries(stats.counters.$server.visitors.count)
B: asPercent(sumSeries(stats.counters.$server.registrations.count), #A)

to see the values... singlestats show:

1. visitors: 24131
2. registrations: 700

3: seleted

delta: 1629.75%

avg: 7.02%

current: 4.35%

total: 3232.60%

so all of them are wrong...

so it seems that it is not getting sum of all from A and sum of all B before doing asPecent?

what I need is to have a direct calculation on totals for A and B and from those 2 numbers get 1 number... 700/24131*100=2.90

so 3rd singlestat should display 2.90%.

it seems tried all the variations possible, am I missing something obvious here?