ArithmeticError: bad argument in arithmetic expression

[sentry-io]

Sentry Issue: LIGHTNING-90

ArithmeticError: bad argument in arithmetic expression
  File "lib/lightning/dashboard_stats.ex", line 96, in Lightning.DashboardStats.step_stats/1
  File "lib/lightning/dashboard_stats.ex", line 60, in Lightning.DashboardStats.get_workflow_stats/1
  File "lib/enum.ex", line 1693, in Enum."-map/2-lists^map/1-1-"/2
  File "lib/lightning_web/live/workflow_live/index.ex", line 87, in LightningWeb.WorkflowLive.Index.apply_action/3
  File "lib/lightning_web/live/workflow_live/index.ex", line 78, in LightningWeb.WorkflowLive.Index.handle_params/3
...
(3 additional frame(s) were not displayed)

(ArithmeticError bad argument in arithmetic expression)