A team needs the percentage of HTTP requests returning 5xx across all instances. Both counters have identical scrape coverage. Which expression is appropriate?

1. 100 * sum(rate(http_requests_total{code=~"5.."}[5m])) / sum(rate(http_requests_total[5m]))
2. sum(http_requests_total{code=~"5.."}) / 100
3. 100 * count(http_requests_total{code=~"5.."}) / count(http_requests_total)
4. avg(rate(http_requests_total{code=~"5.."}[5m]))