Right now the NN participants use the following path when downloading statistic files:

• Download stats for day N from harvester site
• If file is not available, download current stats from project site
• If file is not available, exclude project from superblock

This can lead to missing projects in the block even if they were just out for a brief moment. In that case it might be better to use the stats from the day before:

• Download stats for day N from harvester site
• If file is not available, download current stats from project site
• If file is not available, download stats for day N-1 from harvester site
• If file is not available, exclude project from superblock

Here we can add a few days lookback if we want to, but we should probably keep it very short.