| JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | TOTALS | % CHANGE | ||
| 2008 | 192 | 147 | 213 | 552 | 0.1% | DECREASE | |||||||||
| 2007 | 199 | 152 | 203 | 251 | 255 | 302 | 314 | 236 | 267 | 251 | 202 | 181 | 2813 | 2.5% | DECREASE |
| 2006 | 253 | 201 | 246 | 271 | 226 | 267 | 263 | 226 | 237 | 270 | 215 | 211 | 2886 | 6.2% | DECREASE |
| 2005 | 201 | 189 | 231 | 265 | 260 | 366 | 352 | 253 | 252 | 296 | 210 | 203 | 3078 | 23.1% | DECREASE |
| 2004 | 276 | 229 | 288 | 280 | 368 | 318 | 374 | 344 | 288 | 300 | 266 | 264 | 3595 | 3.2% | INCREASE |
| 2003 | 243 | 158 | 230 | 292 | 343 | 350 | 400 | 328 | 304 | 305 | 231 | 301 | 3485 | 3.1% | INCREASE |
| 2002 | 281 | 180 | 243 | 248 | 258 | 242 | 305 | 326 | 321 | 308 | 283 | 272 | 3267 | 3.1% | INCREASE |
| 2001 | 211 | 169 | 241 | 264 | 288 | 281 | 297 | 304 | 267 | 326 | 268 | 253 | 3169 | 2.9% | INCREASE |
| 2000 | 221 | 231 | 211 | 214 | 298 | 276 | 314 | 292 | 258 | 278 | 233 | 253 | 3079 | 0.8% | DECREASE |
| 1999 | 227 | 233 | 253 | 238 | 229 | 233 | 290 | 311 | 259 | 311 | 275 | 244 | 3103 | 13.0% | DECREASE |
| 1998 | 276 | 253 | 281 | 300 | 343 | 340 | 415 | 328 | 275 | 275 | 244 | 235 | 3565 | 12.5% | DECREASE |
| 1997 | 285 | 290 | 357 | 296 | 345 | 424 | 406 | 430 | 377 | 339 | 245 | 281 | 4075 | 8.2% | DECREASE |
| 1996 | 287 | 287 | 312 | 320 | 394 | 316 | 448 | 439 | 482 | 440 | 381 | 332 | 4438 | 4.4% | INCREASE |
| 1995 | 308 | 258 | 332 | 315 | 332 | 372 | 433 | 439 | 405 | 351 | 311 | 396 | 4252 | 1.0% | DECREASE |
| 1994 | 263 | 251 | 348 | 347 | 399 | 401 | 476 | 386 | 427 | 344 | 354 | 299 | 4295 | 18.2% | INCREASE |
| 1993 | 212 | 233 | 311 | 269 | 277 | 342 | 372 | 351 | 300 | 339 | 310 | 319 | 3635 | 11.8% | INCREASE |
| 1992 | 272 | 255 | 302 | 230 | 218 | 285 | 303 | 302 | 301 | 275 | 231 | 277 | 3251 | 1.3% | INCREASE |
| 1991 | 205 | 206 | 245 | 264 | 248 | 308 | 324 | 329 | 297 | 308 | 238 | 237 | 3209 | 29.2% | INCREASE |
| 1990 | 203 | 176 | 205 | 174 | 235 | 274 | 253 | 224 | 193 | 218 | 143 | 185 | 2483 | 1.7% | DECREASE |
| 1989 | 206 | 188 | 166 | 203 | 226 | 258 | 227 | 262 | 179 | 197 | 230 | 185 | 2527 | 23.6% | DECREASE |
| 1988 | 187 | 271 | 231 | 263 | 293 | 293 | 379 | 338 | 305 | 270 | 231 | 245 | 3306 | 8.5% | DECREASE |
| 1987 | 257 | 223 | 321 | 281 | 289 | 329 | 365 | 407 | 311 | 294 | 285 | 250 | 3612 | 10.1% | INCREASE |
| 1986 | 288 | 271 | 278 | 261 | 268 | 293 | 284 | 294 | 255 | 226 | 283 | 279 | 3280 | 3.2% | INCREASE |
| 1985 | 209 | 180 | 254 | 234 | 265 | 274 | 366 | 324 | 241 | 311 | 264 | 257 | 3179 | 9.1% | INCREASE |
| 1984 | 268 | 210 | 198 | 231 | 243 | 228 | 248 | 293 | 263 | 251 | 234 | 248 | 2915 | 2.9% | DECREASE |
| 1983 | 215 | 242 | 256 | 227 | 230 | 256 | 267 | 335 | 218 | 244 | 257 | 256 | 3003 | 8.2% | DECREASE |
| 1982 | 235 | 202 | 255 | 270 | 296 | 287 | 314 | 324 | 283 | 302 | 271 | 232 | 3271 | 6.0% | INCREASE |
| 1981 | 238 | 256 | 247 | 240 | 284 | 283 | 323 | 274 | 241 | 227 | 250 | 224 | 3087 | 7.9% | DECREASE |
| 1980 | 283 | 198 | 272 | 279 | 271 | 288 | 363 | 325 | 249 | 291 | 210 | 321 | 3350 | 9.5% | INCREASE |
| 1979 | 184 | 182 | 257 | 224 | 294 | 261 | 293 | 288 | 272 | 273 | 261 | 270 | 3059 | 2.9% | INCREASE |
| 1978 | 188 | 156 | 240 | 245 | 266 | 278 | 325 | 239 | 275 | 278 | 246 | 238 | 2974 | 5.1% | INCREASE |
| 1977 | 194 | 174 | 224 | 229 | 283 | 260 | 279 | 247 | 230 | 229 | 263 | 217 | 2829 | 18.7% | DECREASE |
| 1976 | 282 | 238 | 315 | 322 | 321 | 284 | 331 | 362 | 285 | 270 | 218 | 250 | 3478 | 3.4% | DECREASE |
| 1975 | 251 | 253 | 282 | 303 | 276 | 298 | 297 | 366 | 336 | 313 | 312 | 315 | 3602 | 0.9% | DECREASE |
| 1974 | 278 | 213 | 218 | 305 | 286 | 348 | 325 | 292 | 359 | 344 | 367 | 300 | 3635 | 14.1% | INCREASE |
| 1973 | 186 | 159 | 231 | 260 | 294 | 285 | 265 | 362 | 255 | 346 | 240 | 302 | 3185 | 21.9% | INCREASE |
| 1972 | 198 | 221 | 197 | 197 | 218 | 216 | 298 | 242 | 219 | 210 | 203 | 194 | 2613 |