fix social lag normalize by source bug
fix social lag normalize by source bug

thekingofkings/chicago-crime,thekingofkings/chicago-crime,thekingofkings/chicago-crime,thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime,thekingofkings/urban-flow-analysis,thekingofkings/urban-flow-analysis,thekingofkings/urban-flow-analysis,thekingofkings/urban-flow-analysis,thekingofkings/chicago-crime