total sum of fallout caesium-137 in Tokyo

total sum of fallout caesium-137 in Tokyo from 03-18 to 04-29 is 6958.9 Bq/m²
I just added the each day value announced by Tokyo metropolitan government.

source page
http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/index-e.html

I need to convert unit Bq(becqurel) to unit Ci(Curie) to compare the value to Chernobyl age's data.  Curie is a unit  named after Marie Curie. This unit seems to be used as main unit before.

6958.9 Bq/m ²
≈ 7 GBq/km ²
= 7 (GBq/km²) * 2.7*10 ^-11(Ci/Bq)
= 0.189 (Ci/km²)

According below famous Chernobyl map, current caesium-137 in Tokyo is lower level than pink painted zone; 1 to 15 (Ci/km²).
Btw, am I doing the right thing? I am afraid I am comparing between different quality things. Japanese government announce the ground pollution by unit (Bq/Kg).
In Iidate Village which is located very close to the accident plant, caesium-137 of 163,000 Bq/kg was found March. I wonder how large that 1kg mud was lying. If it was sampled upper layer of 1 m² of ground, that place is pink zone. If it was sampled within 50cm square, that area could be purple "Permanent Control Zone" or red "Confiscated/Closed Zone". Suppose the reason  Japanese government use unit (Bq/Kg). Of course i am  conjecturing that the reason is OUR government are hiding bad news because they have no ability to manage/control/run/govern this too bad affair.