Methodology

1. Using terra.transition table and filter event to 'liveness' and get the validators that missed 300 consecutive blocks. Since I'm not able to get any information on how many blocks missed to be considered as offline, we assume 300 blocks since 1 block lasts around 20 seconds. So, validators that are not validating any transaction for 100 minutes will be considered offline.

Over the past 6 months (plus 2 weeks of September), there are 93 different validators that had went offline at least once. Graph below shows the monthly distribution of counts for each validator that went offline.

We're seeing validators went offline the most on month of March and August. Now let's see the ranking for how frequent the validators went offline for past 6 months (plus 2 weeks). Validator block42 went offline the most with over 100 times for past 6 months.