Date slider not doing anything, Objective is to filter data based on slider input and make hist plot

COPY is name of my data frame (libor interest rates fred st.lious), see the picture attached or link below image. Year (COPY[,14]) column is numeric, Earlier I tried working with date type but that didn't work either.

[Click to get the raw data CSV file, and full code to get COPY dataset] (https://drive.google.com/drive/folders/1ZeSqUNfPeqkmGeVdQ_7xRTibSFKYKZmT?usp=sharing)

[DataFrame Head][1]

  htmlDiv(list(
    dccRangeSlider(
    id = 'slider_2',min = min(unique(COPY[,14])),max = max(unique(COPY[,14])),
    marks = unique(COPY[,14]),value = list(1987,2000) ),
    style = list(width = '90%',margin= "auto"))),

  ##Histogram based on date-range obtained from slider 

  htmlDiv(list(
    dccGraph(
      id='basic-interactions_11', style = list( width= '90%',margin= "auto")))),

  ##Callback to filter my data on the date range obtained from slider input
)
  app$callback(
    output=list(id='basic-interactions_11', property='figure'),
    params=list(input(id='slider_2', property='value')),

    function(yea) {
      COPY <- COPY[COPY$Year %in% yea, ]
      traces = list(x=COPY[,2],name= '1 Month',type= 'histogram')

      figure = list(list(data = traces))
      return (figure)

    }
  )


  [1]: https://i.stack.imgur.com/eGVvC.jpg