1year,n_days,mean_yield,mean_change_bp22010,250,2.47968,-0.13654632011,249,2.056265,-0.45783142012,250,1.38004,0.04452013,250,1.62196,0.22862014,250,1.57964,-0.24472015,250,0.8532,-0.24482016,250,0.72628,0.15292017,249,1.363293,0.301205102018,250,2.15132,0.008112019,250,1.53436,-0.0812